Brushless Zero - Mounting an outrunner on a GWS Warbird

I've finally gotten round to installing the brushless engine on the zero, and here is a bit of a post about how it was done.

The Options

There were about three different brushless upgrades paths available (or so I speculated) for my little GWS Zero (which is proving to be such an awesome plane). Here's how I saw them breaking down:

1. Stick mount a geared brushless engine (or bolt a brushless engine into the existing gearbox if one could be found).
2. Use one of the GWS Brushless stick mounts.
3. Remove the engine stick and put a firewall in place to mount the outrunner against.

Option 1 had a heck of a lot going for it. By simply replacing the engine in a gearbox, or replacing the entire gearbox unit you kept your thrustline exactly the same. I even bought a little 4000kv Venom motor to do it. However, when I went to put it in the gearbox I realised a couple of things - the recommended prop was a 10x8 - a 10x8! The Zero will be making three point landings with one of those points being the prop with a 10 inch prop. Further, I didn't have a 350 gearbox I had a 400, s0 the gear ratio would be way too low, and I didn't want to buy a $26 gearbox just to fit a brushless motor too (if I could even find one in the correct gear ratio).

Option 2, using the GWS Mount, seemed like the next logical step. A little bit of measurement suggested that by laying a piece of engine stick width balsa on top of the original engine stick I would get the thrust line just about right. Add some CA and a screw perhaps, bolt in the outrunner and away you go... if only it had been that simple. When I actually measured the distance the prop stuck out the front of the zero (about 5.5 cms) and looked at the brushless mount it was very quickly apparent that I would have to be running the mounting stick into the battery bay, and doing some pretty serious foam cutting so the prop almost lined up. Cutting foam didn't bother me, but I wouldn't be able to get the battery as far forward once the change was made. The Zero already builds a fraction tail heavy, and I was about to put a lighter motor into her. Scrapped that idea - too much work and no certainty of outcome, and the CoG will be very hard to get right afterwards.

So as you can guess dear reader, that lead me to option 3. If you still had your stock 350 gearbox then I would suggest the fastest way to go is get a gearbox mounted brushless. If not, the rest of this post is about how to mount a firewall and outrunner to your GWS warbird (or at least this is how I did it).

The Concept

Because I was worried about getting the thrustline right (slight down and to the right on the Zero) I decided to build a two firewall mount. Firewall one would mount to the fuselage, firewall two would screw into firewall one (allowing me to space and adjust the thrustline using scraps of balsa).

The Job

Here's the Zero with the cowling off. The fibreglass tape is a "tie it up with wire" cleanup from the last serious nose in the Zero had (some time ago now). The photo perhaps starts to give an idea why option two wouldn't work. When you consider the size of the outrunner, the engine mount, the outrunner engine mount stick (which needs to be glued on top of the original engine mount stick) you can see why you run out of space.


So, took off the gearbox (which I'll salvage for getting my Tigermoth back in the air one of these days), and started hacking at the engine stick (which needed to be cut of flush with the front of the fuse). Before removing the gearbox I made careful note of where the prop shaft ran in relation to the fuselage.

Cutting through the engine stick with a hobby knife took longer than you might expect. Let's just say the first photo was bascially natural light, whilst this one was under flash.

The engine mount was cut back so that it was below the level of the fuselage around it. But I didn't want it back too far, as I was planning to secure one of the firewalls into the engine mount stick.

The engine mounts were cut from 3 layer plywood, which was massively overkill for the job, but is what I had hanging about in the garage.

A hole was drilled through the centre of both bits of ply (to assist in centreing on the thrustline). The outrunner's base was mounted to the outer firewall. Aligning holes were drilled through the inner and outer firewalls to allow them to be screwed together later.

Although not obvious in this photo, holes consistent with the postions of the screws holding the outrunner base in place were drilled - to a larger diameter - on the innner firewall. Whether you need to do this will depend on whether the screws securing your outrunner stick through the outer firewall or not. I needed them, otherwise the firewalls wouldn't sit flush.

Once this was done a hole was drilled on the inner firewall above the central hole, and a corresponding hole (taking care to get the position of the central hole correct relative to the original prop shaft correct) was drilled into the engine stick. The inner firewall was then mounted against the fuselage using 5 minute epoxy, and also screwing into the original engine stick.

Looking at the outer firewall in this photo (lieing on the cutting board) you will note that a slot has been cut from the central hole almost to the edge. This will allow the outer firewall to sit flush against the inner firewall without being pushed out of position by the screw holding the inner firewall to the engine stick.

With this done the outrunner was mounted on the outer firewall and the connections made through the hole in the fuselage (after the usual amount of soldering and burnt fingers) to the avionics compartment.

Also in this photo on the top right corner you can see a small scrap of balsa I've put in place with some tape to give the motor down and to the right thrust angle.


The outer firewall was then screwed into place.










Here she is with her cowling back on and a new APC 7x5. I checked out the amp pull with the clamp metre and she came up to about 12A at WOT. Bit dissapointed by that - might need to experiment with some different props later (power plant can do 16A).

About the Motor

The powerplant is an emax 2212 1500kv 16A 60s teamed with 18A speedie. I got them as a package from my lhs.

The 7x5 prop combo may not be the best, as the amp draw wasn't really what I had hoped. On the other hand, a smaller prop with a nice aggressive pitch will tend to suit a warbird. I'm running the Zero on a 3s 800mAh pack that fits nicely into the pre chiselled space for the battery.

Flight Testing

Keen to see how she flew I planned to get down to Curtin with her this morning. Before heading off I took her weight using the kitchen scales - 310g without the battery, so she shed about 40g by getting rid of the brushed 400 gearbox. She was almost certainly going to be tail heavy.

When I got to the field I checked the CoG. CoG maybe just a fraction too far back. If I had tried flying her before, and knew how she handled I might have accepted the balance, but didn't want tail heavy for a test flight. Taped two big washers to the bottom of the cowling. CoG came forward (later I checked the weight - she was 340g - 10g shy of her original no battery weight) and was fine for flying.

Her take off rollout was almost non-existent. As soon as I knew she wasn't going to nose over (a continual problem with GWS warbirds) I opened the throttle and she lept into the air climbing very very quickly.

The performance increase was noticeable, but not out of this world by any means. The Zero was already fairly fast on the 3s 800mAh and the 400 brushed. Overall the performance improvements could probably be summed up thus - about 30% faster, and about another 2s of vertical performance (so a pretty solid 5 seconds vertical from level flight at WOT).

Apart from climbing with the extra power, she seemed in good trim at all throttle positions so I guess I must have got the thrust line about right - woohoo!

Her scale speed is impressive. Whether she will be fast enough to keep up with some of the more serious Eflite kits she tries to mix it up with remains to be seen.

I think that's it for Zero upgrades for the moment. I need to get onto my Tucano and P51.

Opps I did it again

It wasn't my fault. I was just browsing and this gorgeous Phoenix Tucano feel into my arms. It's a balsa ARF that I've had my eye on for a little while now.

The first time I saw it I thought it was a PC9 done in the RAAF (Royal Australian Air Force for Internation Visitors) colours. However, the Tucano is actually another plane, but one that like the PC9 is used as an advanced trainer for pilots before moving onto faster less forgiving aircraft.

In the end I decided that in the sky it would take a good eye and good knowledge to realise this isn't a PC9 Roulette. The colour scheme is very similar, but not idential. If I chuck some RAAF stickers on I will fool most people (except for you of course, dear reader).

Here's the Tucano with her stablemate, an Ultrafly P51 Mustang (both planes have been added to the hangar link now if you want some more details).

The ARF has gone together reasonably quickly, although the usual amount of faffing around on my part has seen some slow progress in some parts. One slightly annoying thing is the engine mount options. The plane is really only built to accomodate one engine, and if you don't have that type (a front mounting brushless outrunner) you aren't using their mount. There is no stick mount, or other easy alternative so I guess I'm building a mount from spare balsa for the RV4.

Saturday here in Canberra - normally a day I like to get some flying done, but the wind does not look good today.

A Brief Distraction

"Hang on a second - that's not a plane. This blog is about RC Flying, not general RC" I hear the readers thinking.

The truth is I just had to share this. I got this little electric powered RC buggy from ebay pretty cheapily (well under $100 including shipping) and it is just an absolute riot.

As you can see next to my thong (thank goodness it's not a photo of me wearing the other type of thong right) the thing is tiny and yet it must be capable of around 30-40km/hr on the bitument out the front of the house. It's got full suspension and AWD. Across the gravel in front of my place (and the river stones for the neighbours next store) you have to use the throttle very cautiously - opening up the throttle will leave stones flying, all four wheels spining and a huge stupid grin on your face. Even after only two full runs through the battery I am actually worried about the amount of stones the thing kicks onto the road.

Few more details - runs an 7.2v 1100mAh NiMH - the charger that came with it was a complete joke - was just a 7.2v 250mAh DC power source with a big warning in the manual saying "make sure you disconnect it after 5 hours or you might damage your battery". Anyway, cut those leads of and adapted them to the swallow so I can now give it a proper peak charge.

I get around 20-30 minutes running time out of it in front of the house. It's not as good as flying, but I don't need to go anywhere for it, which means I can take a 20 minute break from writing documents that no one will ever read (let alone act on) out the front and come back in feeling happy. Unfortunately, going for a fly takes about 1 hr minimum, and is highly dependant on the wind.

In other news the Ultrafly P51 is coming along. Glued on the tail assembly last night, and all control surfaces are hinged. Getting to the stage of finishing servo installation and linkages - it is starting to get close to being finished.

Oh, and one more thing...

I passed 250 takeoffs today. Thinking I should buy a plane to celebrate, but I spose I should get the Ultrafly P51 into the air first.

Hangs Ups

I know - my penchant for puns in titles has to end. The problem is puns seem like such an easy way to be witty whilst writing. Problem is that it isn't actually that funny right?

Anyway, I thought I might show a photo of my new "hangar". I made it on the weekend out of 15mm pressure pipe.

It has taken up more space than I expected, but at least now my planes aren't stacked higgildy piggeldy on top of one another (with the fragile balsa RV4 stacked at the top).

The elebee doesn't get a slot on the hanger, she is away on the left from this photo propped up against the wall.

Speaking of elebees I've switched props on her to a spare electrafun prop - not sure on what it is by spec, but my guess would be about a 6x4. On the weekend in very gusty conditions at Lyneham she was flying very well considering the wind, but I knew I was having to use to much throttle to keep her steady, and eventually the engine slipped the mount, the prop hit the body (no damage) and fell off and I had to make a dead stick landing (which was pretty easy). I haven't had a chance to look yet, but am a bit worried that I may have damaged the speed controller - not too fussed about the engine. Am still looking around for the right brushless engine for the elebee faster than a stryker C project.

Hey, and it looks like the blog has finally been indexed by google - yeah...

The Elebee Project

The purpose of the elebee project is to make my Elebee (Santa's Little Helper) faster than a stryker C.

Phase one of the project is a bigger battery. This I've now done. Am using a 4s 2200mAh 15C LiPo, which should be able to generate aroudn 485Watts when teamed with the right engine.



The new battery just fits into the space in terms of width.



The battery is too high for the canopy to fit in palce, so I've cut the canopy to accomodate it. This should give the LiPo a little more cooling which wont be a bad thing when it is actually working (whereas at the moment it's a bit like Mike Tyson and Bambi squaring off with that poor little 380 class brushed motor at the back of the aircraft).

Bench Checking

Before flying I wanted to check the current flow etc. I could care less about that 380 motor at the back, but I wouldn't want to blow the speedie or even worse the battery by drawing too much current (as unlikely an outcome as that seems).

I did some testing (outside because the pitch of the engine was really annoying the other half) and ended up limiting the up throttle throw to 32% on the JR 2610 (above 32% the 380 started making really really unhappy noises). At that stage the engine was only pulling about 6 amps (so 6 x 14.4 = about 85 watts) on a 5x3 prop. What I found if I went past that point was amp draw suddenly jumped to 10amps, the motor made unhealthy noises (perhaps just cavitating).

Satisfied that neither the speedie (20A continuous/30A burst) or the battery (33A continous) were in any danger I decided to proceed to flying her.

Flying Test

Before flying the elebee this morning I took about 80 grams of washers off the nose of the plane, to allow for the extra weight of the new battery.

I put her up and gave her full throttle. She accelerated quite quickly and was flying quite well. Although I gave her bursts at full throttle, I was mostly using somewhere between 50% and 75% (I don't care about the 380, but I don't want it to start an onboard fire!).

Not really happy with result I pulled her down and decided that maybe the volts were just asking the engine to spin too quickly. I pulled of the 5x3 and stuck on a spare electrafun xp prop (its a spare electrafun xp motor so it seemed a reasonable match). Not having tested the amp draw on this combo I was a little cautious, but nudging her up to full throttle (32% of full throttle really) the engine sounded good, and I could feel the extra thrust.

I gave her a fly - she flew much much better. Very quick and aerobatic.

Liking what I saw I pulled her down and dialled the throttle up to 50% of maximum throw and did another quick flight. She handled the extra throttle with ease, although the speed 380 was still too hot to touch 5 minutes after landing. Maybe some sort of heat sink would be a good idea.

Anyway, back home now - will spend some time with the clamp metre and figure out how many amps she draws with that EF prop.

In other news, put up the RV4 for another flight today and did some inverted flying and loops. It is a beautiful plane to fly - still apprehensive about crashing it through.

PS - An elebee is an epp foam flying wing from Windrider. I bought mine from my lhs nitrodude.

The Glossary

New to RC Flight. Lots of the language confusing. I'm keeping this running space for terms I'm learning. It won't be complete, as I'm just adding to it as I go along, but hopefully it will be useful.


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

AET - Abrieviation for Aileron Elevator Throttle (a 3 channel aircraft)

Alpha - see Angle of Attack

Ailerons - The hinged control surfaces attached to trailing edge of the wing which allow an aircraft to rotate around the length of the fuselage. (see wikipedia for more).

Airfoil - The shape of the wing which causes it to generate lift. There are many different types of airfoil (see symmetric and semi-symmetric below).

Amps - Unit for measure electrical current. See our primer on electrics to understand how amps, volts and power interelate for electric flight.

Angle of Attack - the angle between the wing and the airstream moving over it.

AOA - see Angle of Attack

Attitude - Nose up Nose down (see Pitch).

AUW - All Up Weight - the total take off weight of an aircraft including batteries/fuel/cargo/everything that leaves the ground.

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B

Base - the second part of a three leg landing approach where the model flies across the wind and finalises the position from which it turns to make the "Final" approach into the wind.

BEC - Battery Eliminator Circuit - for electric powered models rather than having a flight pack (see below) the power to drive the receiver and the servos is taken from the same battery that runs the main engine. Often built into the ESC.

Brushed - the traditional type of electric motor where brushes make contact between the rotor and the stator. The touching of the brushes essentially creates the timing and current to make the motor spin correctly.

Brushless - the more moden type of electric motor where there is no contact between the rotor and the stator. A more complicated speed controller is required to carefully feed current in sequence to the magnets to make the motor spin with the correct timing. Brushless motors are much more effecient than brushed motors.

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C

Cavitating - What occurs when a prop spins to fast for the airflow around it and is not longer "gripping" the air as it spins. Typically you need to slow the engine to get grip, and then increase it again later.

CoG - Centre of Gravity - the balancing point for the plane where the "weight" (physics teachers forgive me) of the tail perfectly balances the "weight" of the nose. Planes with CoG too far back tend to snap roll. Planes with CoG too far forward tend to be sluggish in the air.

Control Horn - The small part that connects to a control surface (ruder, evelator, aileron) with holes in it and allows that surface to be moved via linkage from a servo.

Critical Angle of Attack - the point at which the wing stalls due to having too high an angle of attack to the airstream

Cuban Eight - A type of aerobatic manuveur where a plane traces a figure eight in the sky. The sequence of manuveurs is as follows. From level flight, up elevator, half roll, three quarter inside loop, half roll, three quarter inside loop - complete.

Current - the flow rate of electrical energy. Measured in amps - see our primer on electrics.

Cyclic - The control on a helicopter that deflects the main rotor to control the pitch ("cyclic pitch") and roll ("cyclic roll") of the helicopter. Because they make similar orientation changes to a fixed wing aircraft they are sometimes also called elevator and aileron respectively.

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D

Dead stick - no motor power. Often means landing with no motor power.

Delta - aircraft with swept back wings and low profile - built for high speed. Although they often glide well trying to turn at low speed will cause the inner wing to stall and tuck in.

Downwind - The first part of three leg landing approach (see Three Leg Approach below) where the model flies with the wind before turning onto "Base"

Dual rates - A transmitter option that allows servos to be setup to allow for more or less travel depending on whether the TX is in low or high rates. A typical use would be to use low rates for landing, and high rates for extreme manuveruing once at a safe altitiude.

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E

Elevons - A type of setup typically used for Deltas (such as Styker, Zagi, Elebee etc) where each aileron is served by a separate servo, and mixing is done so that the ailerons also act as elevator (for example - to climb both ailerons are pulled up simultaneously).

ESC - Electronic Speed Controller - the thing that controls how much current is given to the engine and hence how fast the engine runs, and the plane flys. Often has a BEC (see above) built in. Note - two main types - brushless and brushed.

Exponential - A configuration option on computer radios which allows the relationship between stick deflection (on the TX) and servo deflection to be made non linear. This allows more delicate control when sticks are closer to the centre position, but still allows full deflection near the extremes of the stick travel.

EXP - see exponential

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F

Final - The final approach for a landing - ideally made into the wind, or across the wind if necessary. Only made downwind in emergencies.

Flaperon - a type of flap setup where if the ailerons are controlled by separate servos on separate radio channels then a computer radio can be programmed to make them behave as flaps as well as ailerons.

Flaps - control surfaces which increase the amount of lift and drag created by the wing for the purpose of landing or taking off.

Flare - The maneuver just before landing where the nose is brought up to extract the maximum lift, and wash off any extra airspeed.

Flight pack - a battery pack which is carried by your plane purely for the purpose of powering the receiver and servos. Typically a high capacity 5 volt type arrangement.

Full Noise - WOT - Wide Open Throttle.

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G

Glitch - radio interference or other electronic control problem making your model not behave according to input.

Go around - going around for another landing attempt.

Ground - something you should aim for your model to reach very gently at the end of a flight, not violently half way through.

Ground Effect - the extra lift that an aircraft gets as it comes into close proximity of the ground (normally around one wing span for fixed wing aircraft). For helicopters ground effect is especially challenging as the lift tends to unsettle the copter making it unstable.

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H

Hammerhead - an aerobatic maneuver where the plane is pulled perpendicular to the ground, and then using the rudder made to fall to the side rather than forwards or backwards when it stalls.

Hand Launch - taking off by throwing the model from the hand.

Heading Hold - a type of gyro for a helicopter designed to control the tail rotor so that it holds the helicopters tail steady by varying the speed or pitch of the tail rotor.

Head speed - a helicopter term which describes the speed and momentum of the main rotors.

Hit - radio interference - a "glitch" (see glitch above).

Horizontal Stabilizer - the horizontal fin which the elevator hinges off.

Hovering - something helis do, and some model planes can also do. Exactly what it sounds like.

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I

Inside Loop - A loop that starts from level flight, involes using up elevator to loop and returning to level flight. The upper part of the aircraft is on the inside of the loop.

Inverted - just like you would expect. Upside down (so the plane's canopy is pointed at the ground).

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J


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K

Kick Point - when flying a hammerhead stall (sometimes called a stall turn) the kick point is the place where full rudder is applied to make the aircraft nose fall to one side.

Knife Edge - a type of aerobatic manuveur where the aircraft is held with its wings perpandicular to the ground, and it's nose pointing up making the aircraft appear to be balanced on a wing tip.

KV - rating for brushless engines - 1000s of RPM per volt. So a 5KV engine would spin at 55,000rpm approximately if you applied 11.1 volts (3s).

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L

Landing AOA - The nose up position that aircraft with undercarriage need to achieve before touching down for a good landing. Also see Flare above.

Leading Edge - The front of the wing. The part that first comes into contact with new air as the plane flys through the sky, hence the term leading edge.

LiIon - Lithium Ion battery. First generation of Lithium Polymer. More stable, can have quite high capacitys, but can't produce current as LiPos can. See wikipedia for more info.

Linkage - The "system" of wire that connects servos to control horns.

LiPo - Lithium Polymer battery. A type of battery chemistry that can support extremely high dishcarge rates. Battery can be dangerous and need to be handled carefully. See wikipedia for more.

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M

Maiden - an aircraft's first flight.

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N

NiCad - Nickel Cadmium Battery - a type of cell chemistry. Must be recycled when disposing as Cadmium is an environmental pollutant.

NiMH - Nickel Metal-Hydride Battery - a type of cell chemistry.

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O

Outside Loop - the type of loop performed starting from level flight and using down elevator until the plane is returned to level flight. The top of the aircraft is on the "Outside" of the loop whilst performing the manuveur.

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P

Piano Keys - refers to the black/white strips which appear at the start of real runways. Aiming at the piano keys means aiming just to touchdown just after the start of the runway.

Pitch (prop) - the distance (normally expressed in inches) that the propellor "cuts" through the air in a single rotation asssuming no slippage.

Pitch (attitude) - rotation of the plane through the axis of the wings (so nose up, nose down).

Pitch speed - The speed at which the propellor pulls through the air. It is calculated by looking at the pitch of the propellor, and the number of revolutions it performs in a unit of time. Pitch speed does not consider slippage, drag and other forces that may affect the aircraft.

Power - For electric models this is a product of voltage and amps and is measured in watts. See our electrical primer for a better understanding of the relationships between volts, amp and watts.

Propellor - the thing that spins. Two ratings on model aircraft. The first number is the diameter (normally in inches) of the propellor, the second is the pitch (see above). So a 7x5 propellor has a diameter of 7 inches, and a pitch of 5 inches.

Pusher - an aircraft where the propeller sits behind the wing. Pushes are often good for beginners as the motor/propeller are not normally damaged on poor landings.

Push Rod - another term for linkage (see above).

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Q



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R

Receiver - see RX below.

Retracts - Retractable Landing Gear.

RET - Abbrieviation for Rudder Elevator Throttle (3 channel aircraft)

REAT - Abbrieviation for Rudder Aileron Elevator Throttle (4 channel aircraft)

RoG - Rolling over Ground - taking off using undercarriage.

Roll - the rotation of the model through the axis of the fuselage (so left wing tip up/right wing tip down and vice versa).

Roll rate - how quickly the model can perform a roll by using ailerons, or aileron and rudder.

Rotate - lift off, pull back on the elevator, get off the ground already.

RX - Receiver - that thing in the plane that means it will actually do things when you tell it to with the transmitter (TX)

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S

Semi-symmetric airfoil - a type of airfoil which generates almost as much lift when the plane is inverted as when it is flying normally.

Servo - the small motor with control arms that responds to input from the receiver to actually do the mechanical work of moving a control surface or throttle.

Speedie - Slang for the Electronic Speed Controller (ESC) - see above.

Spin - a maneuver (often entered involuntarily due to a stall exaggerated by a yawing force) where the aircraft is rolling with its nose down rapidly losing altitude. Spins are recovered by closing the throttle, and if necessary adding opposite rudder. Once the spin is correct power can be reapplied.

Stall - The point at which the wing no longer produces lift and the model's nose falls.

Stall Speed - the speed at which the airstream passes the critical angle of attack and the wing stalls.

Symmetric airfoil - a type of airfoil which generates the same amount of lift when the plane is inverted.

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T

Tip stall - a stall where a wing tip is dropped rather than a straight through stall where the nose drops. Tip stalls are harder to recover from than straight through stalls.

Three legged approach - an approach for landing with three distinct phases - Downwind (see above), which turns onto Base (see above), before turning into the wind for Final (see above).

Thrust - the force produced by the propellor, ducted fan, turbine, whatever. Is measured in grams (at earth standard gravity of course) or ounces (for imperial measures).

Trailing Edge - The edge of the wing that is last in contact with air as the plane flys. Hence the term Trailing edge.

Transmitter - see TX below.

TX - Transmitter - that box with the sticks on it that allows you to control your plane.

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U

Unlimited Vertical - a state of model aviation nirvana where a model has enough power to fly perpandicular to the groud (vertically) for ever (excepting battery/fuel/radio range limits) without stalling. This is significant because the wings are generating no lift to fight gravity when the aircraft is perpendicular meaning the engine alone is creating enough thrust to overcome gravity.

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V

Vertical Stabilizer - the upright fin which the rudder hinges off.

Voltage - electrical pressure - measured in volts - see our electrical primer for a better understanding of the relationships between volts, amp and watts.

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W

Washout - a design feature of many wings where the wing tips have a lower angle of attack than the wing root, causing the wing root to stall before the tips leading to a gentle straight through stall.

Watts - a measure of power. Is the product of volts and amps - see our electrical primer for a better understanding of the relationships between volts, amp and watts.

Wing Loading - the all up weight (AUW) of the aircraft divided by the surface area of the wings. Lighter wing loading generally means the aircraft will get more lift with less speed.

WOT - Wide Open Throttle 8-) You can probably figure out what that means.

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X


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Y

Yaw - rotation around the vertical axis of the aircraft (that is perpendicular to the wings and the fuselage - so nose left, nose right).

Y lead - a cable that allows two servos to be controlled from a single channel. Used when you have an aileron plane which takes separate servos on each wing.

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Z


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Electrics of Electric Flight

I'm trying to write down all the good stuff about electrical powered flight which other people have taught me, so that it might be useful to others coming into the hobby. So without further ado:

Electrical Basics

When it comes to our electric flight there are four things we typically think about:

Voltage
Current
Power
Capacity

As you probably know there are other electrical things that you might normally measure, like resistance etc, but we don't normally need to worry about them for electric flight.

The easiest way to think about all these things is to imagine electricity as water.

Voltage is electrical "pressure". It is measured in volts (v). Thinking of it like water, voltage is the the number of metres of pressure you have - so if the resorvoir is 50 vertical metres above you, you have 50 metres of pressure.

Current is electrical "flow". It is measured in amps (A). Thinking of it like water we would measure it in something like litres per minute.

Power is the combination of voltage and current (power = volts x current). We meaure it in Watts (w). This is easy to imagine with water as well. Think of one of those huge water wheels - the kind that were used to power saw mills in times gone by. Now imagine hitting it with a super soaker water pistol. Even though the water is at very high pressure, there is very low flow, and so the super soaker will probably not generate enough power to turn the wheel. Now imagine the gently babbling stream that feeds the wheel, and under the force of almost no pressure, but with a high enough flow rate, generates enough power to turn the wheel. Finally imagine the firehose - the best of both worlds - high pressure and high flow rate - it would probably make the wheel spin quite quickly.

Capacity is a measure of how long you can draw a specified current from a battery. It is measure in Amp Hours (Ah), or more commonly for the scale of equipment used for electric flight, mill-Amp Hours (mAh). Using the water analogy this is simply how many litres you have in your reservoir. It is a little more complicated for electrical power and we will talk about it a bit later.

How Much Power Do You Need to Fly?

To figure out the power you need to fly a model depends on the weight of the model, and the type of model it is, as well as what you want from it.

In one of those quaint exposures of the inadequacies of the Imperial measures system which the US still cherishes this is normally expressed as Watts (a metric unit) per pound (an imperial unit). For those that want to work with a measurement system that makes sense, one pound equals approximately 450g for the numbers below.

50-70 Watts per 450g - Minimum for reasonable performance flight. Slow flyers and slow park flyers
70-90 Watts per 450g - Slow flying scale models, Trainers.
90-120 Watts per 450g - Sports aerobatic. Fast scale models.
120-150 Watts per 450g - Advanced aerobats. High Speed Models. Excellent Vertical performance
150+ Watts - Very High Speed, Unlimited Vertical Performance.

Note - You must include the weight of all the plane's components in your calculations - anything that leaves the ground with the plane needs to be included - batteries, the engine, speed controller, etc.

So, if you have a 900g delta wing, that you want to have unlimited vertical performance, you are going to have to try and generate 300w (900/450 = 2, 2 x 150 = 300).

If you have a slow flying scale plane that weights 350g then you need to try and generate a minimum of 54 watts (350/450 = 0.77, 0.77 x 70 = 54).

Understanding the Limits of Your Equipment

Most electrical equipment will have limts on the amount of current it can handle, as well as sometimes the number of volts it can handle. Some equipment also states a power limit as well.

Batteries, and particularly the Lithium Polymer type, are rated in C for the amount of current they can discharge. So, if you have an 800mAh 20C battery the maximum current you can draw from it is 16A (20 x 0.8=16). With the battery's volts in hand (say a 3s 800mAh rate at 20C) you can generate the maximum power this battery can provide - 16A at 11.1v = 177watts. Batteries may have a burst rate, and a continous rate - so 15C at burst, 10C continous. Using the 800mAh battery again you might be able to draw 12A in burst, but only 8A continously.

Speed Controllers are often rated by the amount of voltage, and current they can handle. The amount of current that is drawn through the speed controller depends on the engine. In general you need to make sure your speed controller can handle at least as much, and ideally a little more current and power than the engine. Obviously your speed controller needs to be rated at the voltage for the battery - it will not reduce voltage either (there isn't room for a transformer there).

Engines are usually rated at the maximum current draw they can handle. They will often have a burst and continous rating. Sometimes engines are also rated for the maximum power they can handle. For example, and engine might say 18A or 200watts. This engine could handle a three cell LiPo (11.1v) @ 18 A = 198watts, but couldn't handle a 4 cell LiPo (14.8v) @ 18A (266watts). However, if you restricted the throttle so that the current never got above 13.5 A you could use a 14.8 volt battery with the motor (provided the motor can handle 4 cell LiPos).

How Much Current Does An Engine Draw

The current an engine draws depends on the propellor it spins and gearing. Generally if you buy a new engine information on propellor combinations, and how much current they draw will be included.

If it isn't, and you can't find it on the Internet, or you want to experiment with a different propellor then you really need a way to measure the current flow to make sure the engine is not drawing too much current for either the battery, the speed controller, or the motor.

If want to measure your current draw you will probably find that most cheap multimeters will only do 2 or 3 amps. I use a clamp meter, where the clamp is placed around the positive lead from the battery, and the current is measured through magnetic inductance. This has the big plus of being a lot less hassle (because you don't have to connect the metre in series) and a lot safer (as you aren't messing around with bare wires). Can strongly recommend a clamp metre if you are into this stuff.



Propellors with a larger diameter will draw more amps because they are moving more air. Propellors with a more aggressive pitch will draw more amps to a point, although the best pitch for a propellor is normally determined by how fast the engine spins (the kv rating for brushless engines - 1000 of rpm per volt).

There are two ways to reduce the amps a system draws - reduce the prop size, or limit the throttle throw if you have a computer radio.

A note on props

Props have two ratings, and by now you have no doubt figured out the first number is the diameter in inches. The second number is the pitch. What this number actually represents is the number of inches that the propellor would advance through the air in one rotation assuming no slippage.

Choice of propellors can significantly change the way an aircraft behaves. For example. A big propellor will give your aircraft a lot of thrust, and allow it to reach top speed very quickly, but top speed will be quite limited. A smaller prop will take longer to accelerate, but will have a higher top speed. Which prop you need depends on application. For a 3D model typically you are after thrust and quick acceleration. If you are building a warbird, you will probably favour higher speed at the cost of acceleration.

A few more thoughts on batteries

Flight times and capacity

If you know how many amps your model draws whilst "cruising" it is pretty easy to estimate an approximate flight time. For example, if you have an 800mAh, which draws 8A while cruising you will have an approximate flight time of 6 minutes (800/8000(8A)=0.1 of an hour, or 6 minutes).

Our model of imagining a battery as a reservoir of water holds pretty well for a lot of examples, but not under all circumstances. For example, given two batteries - a 2 cell 1200mAh LiPo, or a 3 cell 800mAh LiPo, which would provide the longest flight time.

The answer is perhaps not as simple as you might think. Because the 3 cell has higher voltage you do not need to draw as much current to achieve the same power.

Let's say you need 30watts to cruise your light parkflyer:

For the 3 cell: power = volts x current therefore 30 = 11.1 x A, A =30/11.1, A=2.7
For the 2 cell: power = volts x current therefore 30=7.4 x A, A=30/7.4, A=4.1

So, flight durations are as follows:
3s 800mAh: (800/2700=0.3 of an hour, or about 18 minutes)
2s 1200mAh: (1200/4100=0.3 of an hours, or about 18 minutes)

So, even though the 2 cell has higher capacity, because the current draw is so much higher to provide the same power, it ends up both these batteries have about the same flight time.

Got questions - think I am wrong about stuff - post it as comments and I will update this page.

Other Info:

Paul Daniels from NQRC has this useful info on this site.

More RV4 Goodness...

More RV4 flying this morning. Was working on getting the flap elevator mix correct. About 60% flap and 18 elevator (on a JR x2610) seems to be making an appreciable difference to lift at slow speed, but stopping the nose pitching forwards which I have talked about before.

The result is a plane that can be brought in at quite a slow speed to land, which I know will make things easier in the future.

I nosed the RV4 over on one of the really bad landing attempts this morning, but she was okay. In some ways she is tough. In others, looking at her nastily will cause all sorts of issues.

On all four takeoffs today she dipped a wing slightly, but full power and plenty of elevator saw her safe at altitude. I'm not used to paying so much attention to planes at takeoff (excepting the endless nose overs the zero does). With a foamy takeoff just normally isn't that risky. You aren't going that fast, and even if the worst happens it will glue back together quickly. It would seem things are a little difference when it comes to balsa planes.

Very happy with the way she flys - was a little more relaxed today and enjoyed the flying a little more. Did a victory roll - no probs. And her colours actually make her really easy to see, even at distance - quite a lot of fun.

The Zero did a few more sorties on the new LiPo. I think I set up the CoG a bit better today because I was much happier with the way she was flying. Not as good as the RV4, but the Zero is foam after all.

Getting a bit sick and tired of these nose overs on takeoff, but I'm just not sure there is much that can be done with a park flyer scale foam warbird. I tried hand launching the zero today - mini disaster. She plowed straight down into the ground. Only damage was a busted prop so nothing to major there, but suggests that over arm hand launching is not really an option. Maybe the underarm fling is the way to go.

Spent a little more time with WOT on the Zero today, and she is actually a pleasure to fly with the extra poke (and the CoG right it would seem). Actually did an outside loop today. First time I've been able to do that since I replaced the 350 with the 400 (which it turns out was a bad move...). I did a low level pass or two with the Zero - she has enough poke to be a contender now. Now I just have to figure out whether I want to burn out all my brushed motors before going brushless, or whether that needs to happen straight away.

She's back

She can be rebuilt

After speaking to Paul @nitro yesterday he described my plane's damage as "a flesh wound". I was surprised, but I did persist in trying to put her back together. I had some time on my hands yesterday for various reasons and so poked along for much of the day.

The first problem was the two forward bulkheads being smashed by a combination of the engine mount being torn out, and Mr LiPo teaching a lesson on the rules of inertia. I started reconstructing the foremost bulkhead using the bits of balsa I collected at the scene.



Here's the forward bulkhead after I had pressed a few bits of balsa back in. Note, the balsa sheeting and framing in this part was never seriously damaged. My main concern was getting the thrust angle right.

The front bulkhead pressed back together pretty well from pieces and was secured with thin CA.

However, the rear of the front two bulkheads was more badly damaged, and I couldn't find all the pieces (although I was sure I collected *everything* at the field. Anyway, before I did any work she looked like this:



Unable to successfully assemble the parts I had for this bulkhead I took a different approach. My main problem here was building a space for the rear part of the engine mount to connect to. By using the parts I had I was able to measure approximately where the mounting point should be (the RV4 has right and down angle on engine thrust).

Rather than try and rebuild the whole bulkhead - given it was still strong as it stood, I used two long pieces of balsa running vertically between the bits of wood that still existed in the bulkhead and the correct width for the engine, allowing for the offset. These were secured with thin CA. Two much shorter pieces then crossed these spars horizontally giving the "box" to secure the rear of the engine mount in. Once again, these pieces were slightly above the whole in the front bulkhead to allow for the down thrust angle.



Of course the cowling was smashed, but nothing but a little sticky tape and plastic model airplane glue couldn't fix.

The stringers where resecured using thin CA. The top string was augmented by the presence of the canopy ply/velco connectors, which meant it all joined together quite strongly. The joint was reinforced by using bits of balsa between other parts of the frame. The spars that support the battery tray also came away (with the battery tray), and so these where put back in place and secured using thin CA.

She has been rebuilt

So, here she is at Curtin Oval this morning:



The Flight

Well, it was a bit of a model plane regatta. I was hoping a mate might come down but no doubt real world matters interferred. I took 4 planes - all 4 that are servicable. The RV4, The Ele-bee, The Zero, and the Electrafun XP. The 3 extras where to give me some flying if the worst happened.

The RV4 was on a new prop today - an 8x4 - a better fit for the towerpro brushless according to the Internet.

Before the RV4 flight I double checked all the control throws and neutral positions (as well as the usual range check etc). I noticed she had a little up elevator dialed in, but assumed I put that there on purpose previously. I gave her a little throttle to get her moving. As she started to get airborne she dipped a little to the left - oh crap - not again. Full power, and elevator, and a little right airleron. She screamed up to 15 metres. Safe for the moment.

Throttle back to about 40%. Plane is still climbing Remember the elevators and give her three clicks down elevator. Still climbing. Another two clicks - settled. She is rolling to the left. Couple of clicks right elevator - flying straight.

Now I actually notice how much faster she is with the 8x4. Frightening fast really - even at 1/3 throttle.

Apart from climbing she seems to fly straight and level at 1/3 throttle or WOT - good news - I have the thrust angle near enough.

I put her through one loop. The rest is just flying backwards and forwards. I can't figure out whether she is flying as well as last time, or whether I am just nervous, but she doesn't feel quite right. But still okay.

I try to bring her in to land. Flaps on. She pitches the nose down - too much, and after one or two failed approaches I decide on a no flaps landing, even though she is fast.

On the first real landing I get a wheel on the ground but she pulls up as I was flaring, I wave off and power up to go around.

Second approach is better. She touches down moving quite fast. I accidentally put her back into the air with up elevator (to hold the nose down and stop a nose over). She comes up abit, and from about 6 inches up stalls and lands a little awkwardly and noses over. However, no damage, and she is down.

Things to do

I'm going to try and dial in some elevator compensation for the flaps. My radio can do it, and the way she pitches forward with flaps is a little disconcerting.

I'm not sure I have the rudder right, and have a feeling that is some part of the "unease" of her flying.

Otherwise, very happy with her second flight. In a lot of ways I preferred the 9x4.7 - high thrust but lower speed - she just handled like she was on rails. But the 8x4 is a better match for the engine - it actually gives me full throttle play and jee she is quick at WOT.

Other News

The Zero has been upgraded to a 11.1v 800mAh battery. I checked yesterday, and it fits the GWS Zero battery compartment very snugly (so snugly I looped a piece of string round it so I could pull it out). This has given the Zero a lot more poke.

This is the first stage of Zero upgrade project. The next is a little brushless engine (yes, she was on brushed today), but that may have to wait a little bit. So current setup is 8x6 prop on GWS EPS400C BB C Gearing with 11.1 800mAh 20C Battery. Flight times are unlikely to be much shorter than the on the venom 7.4 1250mAh battery - less mAh, but I can draw a lot less current to achieve enough power due to higher voltage - of course with the extra juice I can burn the power much more quickly if I wish.

She had pretty good vertical performance actually - I was surprised.
Anyway, more on that later.

We can rebuild her

Well, more accurately - we have rebuilt her. The RV4 is ready for re-maidening today. Hopefully some of my maiden flight luck will return. Remains to be seen I suppose.

The repairs took a large chunk of time, and although I am mostly quite happy with the way she went back together I am a little concerned about the thrust line, and also concerned about whether the crash has weakened other parts of the airframe. I did my best to build in the down and to the right thrustline, but I could easily have over done it in both cases.

Heading down to Curtin to give the RV4, amongst probably most of my planes, another fly this morning. I have a new 3s 800mAh battery for the zero, which will have quite a short flight duration, but which should be quite quick and entertaining whilst it is flying. If I draw 10 amps I'll only get about 4-5 minutes flying. It will be brushed, but with 11.1 volts that will be about 110Watts, which should make the little zero fly quite well. There really was no scope for a bigger battery - the compartment on the zero just wouldn't handle it.

Could this be it for the RV4...

Well, after 40-50 hours of construction effort, and the fantastic maiden flight last Saturday morning, the RV4 lies in pieces on the dining room table, and I have my doubts that she will ever fly again.

It was only her second flight - it lasted all of 5 seconds. Needless to say I am feeling a bit sad about her loss, but I can tell that I am a bit circumspect about it as well. Funnily enough writing this post seems to help.

So, what happened? It's a good question. After having her beautifully trimmed last flight at Curtin, takeoff was the last thing I expecteded to have trouble with.

The Crash

I was letting her accelerate at about 1/3 throttle. Flaps were on. As soon as she was airborne she started dipping to the right (quite a bit). Now here is were a certain amount of poor planning on my part entered the equation.

At Curtin there is a large steel pole in the middle of the field for no apparent reason. I sometimes refer to it as the intentional hazard to model aircraft navigation because it doesn't seem to do anything else.

I had walked far enough so the plane should easily pass the pole on her right hand side as she took off. Problem was that with her banking sharply to the right I suddenly had two problems - 1. restoring level flight and 2. not crashing into the pole. I am confident that even with my low level of experience I could have dealt with 1. I'm very angry at myself for not walking far enough to make sure two wasn't an issue at all.

So, she didn't hit the pole, but somewhere between trying to turn her sharply enough to restore level flight, but avoid the pole, and forgetting to increase the throttle she ended up on the ground. I think she clipped a wing tip or maybe a wheel pant which cart-wheeled the nose in.

The Cause

The crash scene investigators have concluded:

The primary cause - the thing that caused the right hand bank on take off, was that somehow the left hand airleron linkage had been moved (the V bend pulled a little away from the wing) pulling the left hand airleron down at the neutral point. No doubt with the flapperon on the effect would have been exaggerated. No I didn't make sure the left hand airleron was neutral before take off - bad ozrcboy - bad.

The secondary cause was the pole - if it hadn't had been there I might have been able to compensate long enough to get her on the ground safely. Instead I was fighting a banking plane, and trying to avoid the pole.

Needless to say if I had either done my preflights properly, and made sure I was well clear of the pole, I might still have a flying airplane.

The Damage



Well, it certainly doesn't seem that balsa bounced for me. The damage is extensive. As you can see the nose has separated from the main fuselage. The engine mount has destroyed most of the two forward bulkheads whilst tearing itself free.

I honestly don't know whether this can be repaired. I'll take the remains down to LHS this afternoon and discuss options. I really don't want to throw away this bird, not after so much effort has gone into her, and not after her maiden showed so much promise.

The Pledge

Just after the crash I thought to myself - well, I'm through with balsa. Already I'm rethinking that. Already I'm feeling ready to get back on the horse. It would be nice to get back on this horse, but we will see what comes.

Raving about the RV4

At around 8:30am this morning I maidened my RV4 - the culmination of many (elapsed) weeks of effort. The wind was very light (2 knots or so), the sun was shinning brightly - maybe a bit too brightly, but I would just have to keep the plane out of the sun. She was ready to roll, I'd had the controls checked by another flyer, CoG was set, the taxi test on the grass had worked just fine. There was no time like the present...

Specs on My RV4




Controls: 4 Channels (I've mixed in 5 to allow Flaperon setup with those big wide airlerons)
Battery: Model Engines 3s 1500mAh LiPo
Power Plant: Towerpro BM2408-21 13A 1750kv Brushless Motor and TowerPro Mag 8 18A Brushless ESC.
Prop: 9047 I tested with (because I couldn't get the recommended 8x4 or 9x4 at short notice).
Receiver: JR RS77S
Servos: Hitec HS55 throughout (2 x airlerons, rudder, elevator).
Takeoff Weight: 544g including battery pack (402g without pack).



About the RV4

The RV4 is a balsa StevensAero kit that I purchased from Nitrodude (http://www.nitrodude.com.au). It is a scale replica of the real RV4 Kit Plane from Van's Aircraft (more info here http://www.vansaircraft.com/public/rv-4int.htm) which amongst other things was the first kit plane to be flown around the world by Australian Jon Johansen in 1995 (more info here http://www.vansaircraft.com/public/jj-persn.htm).

Building It

If you want to build a balsa kit these SA kits are simply amazing. They almost snap together and they self jig - this is the first balsa model I had ever built, and it built straight without me 1. knowing what I was doing, 2. worrying about whether or not I was building it straight.

There were a few mishaps along the way. For example, I put the airlerons together the wrong way round first time because I was so tired (which some careful cutting and regluing fixed), and I snapped a rib of the fuse twice (which straightening, hardening with CA and reinforcing with another bit of balsa fixed) due to heavy handling, but for the most part it was hard to go wrong.

Covering the model was another challenging thing to learn. Fortunately the photo resolution for pictures on the web wont let you see the ugliest parts, but this shouldn't make much difference to how she flys.

The model has two motor mount options, allowing you to fly her on a GWS350 geared setup, or install a brushless straight away. I went brushless straight away with a little TowerPro 2808-21 (my first brushless engine). I was unable to get the best props on short notice, so ended up using a GWS 9047. I was worried this might draw too much current, but some time on the desk with the new CLAMP meter showed she wasn't going to bust 13A (although she was at max throttle at around 75% of throw of the throttle stick.

Once assembled, pushing the flight battery, a 3s 1500mAh as far forward in the compartment left her perfectly balanced (for the maiden) a fraction forward of the main wing spar.

The day before the maiden I took her back down to Nitrodude for a final control and control throw check. After discussion we dialled back the throws another 30% (good call - thanks Paul), and I halved the flap deflection.

All the preflights were done - CoG well set, control checks done. Flaps on. I tried a test taxi on the grass at Curtin - all good. Look around the field, check the wind, deep breath then... advance the throttle.

The Maiden

With about 1/3 throttle she quickly built up speed and was airborne a few moments later. Putting throttle up to about a half I used some more elevator to get her to put on some altitude. At about 10 metres I had to turn her due to configuration of the park. Nice gentle roll rates thanks to backing off the throws. Fumbled round for the flap switch - flaps up - model looking steady.

Very slightly rolling to the right - dialed in 1 click left airleron - steady now. Slightly nosing down - 1..., 2... clicks up elevator and flying well..., in fact flying brilliantly. She was reacting absolutely perfectly to every instruction I was giving her.

Sailed her up and down the field and put her into high banked turns - she was inspiring confidence. Not wanting to get ahead of myself there are a number of things I wasn't going to do on the maiden - use high rates, or do any kind of aerobatics. Two things I was going to try were WOT (I was still flying her easily at 1/3 throttle), and vertical performance. I pushed to WOT, planning to leave it there for only 5 seconds or so - the extra thrust bumped the planes speed up, but very quickly I could tell the prop was not right for high speed (although she was still making pretty good pace). Brought her back to about 1/3-1/2 throttle, gave her WOT and pulled her nose up. Up she went to vertical. Hoping for her to keep on climbing I watched as she hung in the air - me using the controls to keep the nose straight up. She hung there for about 5 seconds before finally stalling away to a nice easy recovery.

I'd only been flying about 5 minutes tops, but I wanted to bring her in long before I had any battery issues. Eased the throttle back, check wind, work out approach, flaps on. She got a slightly nose down attitude with flaps on, brought her round and brought her in at about 1/4 throttle. Approach was no good, running too long, had too much airspeed at the bottom of the dive. Power on and pull away, and round we go.

Realised also that the wind had changed direction (although still very slight), flew to setup a new approach. Throttle down dive - too long again - probably plenty of room, but I want to be close enough to see contact point, and I want *plenty* of room. Call that one a practice, power on, round we go.

Next approach, much better, looks good, plane down from altitude much sooner - still running longer than planned, but there is the aforementioned *plenty* of room still available. Realise this is the one - flare, good contact, no nose over. Close throttle. Collapse.

Before starting the flight I had joked with my better half about whether my maiden flight perfect landing blessing would continue (The last four planes I've maidened, including the RV4, I have had perfect landings - planes that I later badly damaged due to poor landings such as my Tigermoth 400). Well it held - I was ready to live with a nose over landing and no damage, but in the end the landing was much better than that. Down safely for a perfect landing. Woohoo.

Closing Thoughts

Balsa does fly best. Well, and having enough power makes a plane fly properly also, but I couldn't believe how direct the RV4 was - it just went exactly where I wanted it too. I'm looking forward to getting it back out to the park.

Folding Under Pressure

Well, a funny thing happened at the field today. I was flying with a mate - me with the elebee and him with his Electrafun. He was messing around doing some continuous stall turning and zooming and had built up a terrific clip of airspeed. I was focusing on what I was doing but got a glimpse of his plan out the corner of my eye, and was immediatelly concerned about how much flex his ship had in the wings. Not a moment of thought later, snap. Wing folded and down she came - spiralling earthwards, and crash.

Thinking he had folded it out on one of the tips I reminded him about the need for tape, but I'm not sure tape would have helped. He busted the spar almost immediatelly above the fuselage, and that is where the wing broke through - just amazing. Should have snapped a picture - didn't - oh well. Needless to say, the Electrafun was basically undamaged otherwise from its 30 metre plummet to the ground - what a ship.

Was trying some different props on the elebee today - a GWS 5x3 and a spare electrafun prop - my opinion - neither was as good as the stock prop. Bit dissapointing. Maybe a 5 x 5 might be better suited, if such things exist.

Have ordered quite a few new things this week. A cheap brushless motor/speedie combo is on its way, as is a 25Amp speedie (with the duck's guts of BEC), some more 36.550Mhz Crystals and a new receiver. Much of this is aimed at having the necessary components ready for the arrival of my Ultrafly brushless P51 Mustang (which my other half has confirmed I am getting for my birthday - woohoo).

The Electrafun Review

Contents

1. Introduction


2. The EF Summary and Pros and Cons


3. About the Plane


4. Where do I get one/How much should I pay?


5. Common Problems with your new EF


6. Prepping Your Electrafun Before it's first flight


7. Your first flight


8. Aerobatics - what the EF can do


9. Upgrades and Hop Ups


10. Other EF and first flight resources

Introduction

Much of the traffic to the blog seems to be people looking for info on Electrafun XPs. Based on this I thought maybe I should do a review of some of the stuff I have written about the EF before (I'll use EF as a shorthand for Electrafun XP throughout). Rather than changing what I have written previously, I'm doing a more complete posting of lots of stuff.

Pros and Cons

So, trying to give a summary of suitably brief length to suit the ADD generation:

Pros:

• All in one kit at quite a cheap price.
• Super fast to assemble - the longest part is waiting for the battery to charge.
• Flys really really well.
• Quite quick (although can fly slow too).
• Very resistant to crash damage (make sure you prep it - see below).
• Can do some moderate aerobatics.
• Plenty of spares.
• Forgiving handling.

Cons:

• Kit quality can be a bit random in my experience. Plane is built for a price and shows it.
  
• Avionics are rubbish - for some reason they work just fine in the EF, but moving them to any model you value will end in tears.
• The Ni Cads provided with the kit do work, they just don't work well, or for particularly long. Fortunately new battery packs aren't terribly expensive

About the Plane

The EF is a three channel electric powered trainer which in Australia is distributed by Model Engines. Elsewhere it is known as the JP Electrafun XP I believe.

It is a complete RTF kit including:

• Four Channel Transmitter (27Mhz)
• Complete airframe with motor, avionics and linkages installed
  
• Two wings (which are attached to the fuse by rubber band)
• Two tail assemblies (vert stabiliser/elevator, horizontal stabiliser/rudder) with horns installed.
  
• Undercarriage (trailing wheel style)
• Two 8.4 v 650 mAh Ni Cad Battery Packs
• Peak Charger (requires 12 volt supply - either car battery or 240VAC to 12V DC converter)
• Two propellors
• DVD (in Australia only maybe)

It is pretty good value in the sense that you do get everything you need to fly (well almost - see below for prepping the plane) however, there are some notes below about that in the "where to get it" section.

How Much and Where to get one

My own thinking here is still that if possible you should buy from a hobby shop in your own city - even if it is online. The main reason is that the quality on the kits does seem to be a bit random. For example, my kit had a dud charger, and so I was able to go straight back out to LHS and get it replaced.

Seems the price continues to come down on this. Anywhere between $130 and $150 at the time of writing seems reasonable.

There is a cautionary note here. A salesperson might try to convince you that one of the reasons the EF is such a bargain is because you can take the electronics to another plane. My own opinion is that, for some reason in the EF the avionics seem to work quite well in situ, but they are rubbish and don't seem to work at all well outside their natural environment. For example, even though it has a 4 channel receiver, I wouldn't use it in any 4 channel model you value. My GWS Tiger Moth took at least 3 serious crashes before I gave up trying to "save money" by using the EF avionics in another plane.

Common Problems

When I say common I mean either I have encountered them, or someone has told me about them.

Control Surfaces Not Aligning

Before trying to fly your EF you need to make sure the control surfaces (the rudder and elevator) line up with the vertical and horizontal stabiliser. If you find that after using the trim tabs on the radio that the control surfaces still don't line up then you will need to make some mechanical adjustment.

Put some long nose pliers onto the small upright piece of the control rod and twist to either sharpen or open the angle depending on the direction you need to adjust the control surface.



Don't try to fly if you can't set your control surfaces to neutral. In fact you shouldn't really try to fly unless you can go a little past neutral in each direction. This is because even though the model may be trim by eye, it is whether or not it flys straight that is the final arbiter on when it is in trim.

Elevator not Parrallel

You may find that after putting it together that your elevator is not parrallel to the wings. It seems that almost every EF has some sort of twist in the carbon fibre boom. I don't actually know for sure, but the way it affects every one I have heard about suggests that some of the twist is actually intentional.

If the elevator seems significantly out of alignment, then you can use something glued to the top on one side of the horizontal stabiliser mounting piece to level the horizontal stabiliser. I used some modelling plastic I had hanging around. Very thin bits of timble, cable ties - use your imagination and the contents of your kitchen draw.

How parrallel does it need to be - not perfectly, but it should not be casually observable that it is a long way out alignment with the main wing.



Sorry this isn't a great pic because it is inside the focal length of my camera, but if you look closely at the left hand side of the horizontal stabiliser mounting block (the white thing on the end of the black rod) you can see how I have built up one side to level out the horizontal stabiliser/rudder assembly.

Rudder not square

This problem leads on from the last. If the horizontal stabiliser mouting block is not perfectly horizontal then the vertical stabiliser rudder will also be out of alignment. Like the elevator, it doesn't need to be perfectly square, but the closer the better.

To check the rudder, once the wings are on look down the nose across the top of the model and see whether the indicator arrows on the wings line up with the rudder (make sure the wings are one straight!). If the rudder looks to be within a few mm of square (less than 5) once you have corrected the elevator then I would suggest you don't worry about it - that should be near enough. If not you have two choices. You can either 1) try to straighten it yourself or 2) take it back to LHS (see why buying from LHS isn't such a bad idea) and ask them for their opinion/help correcting it. If it really isn't straight it really is up to them to either make good the one you have, or replace it with one that is straight (or at least straight enough).

If you try to straighten it yourself, pull the vertical stab/rudder assembly out of the boom and use some pliers to very carefully and slightly bend the connectors. Make sure you hold the rudder by the bottom plastic mounting while doing this. DO NOT TRY TO ADJUST THE RUDDER WHILST IT IS INSTALLED IN THE BOOM - Carbon fibre does not like to twist and could shatter.


Prepping Your Plane

Before flying your EF I would suggest the following additional preparation steps.

1. Use the tail undercarriage, but don't install the main undercarriage - the EF hand launches well, and for the moment you don't want to worry about attempting ground landings. The tail undercarriage helps hold your horizontal stab/elevator off the ground and so is worth installing.
2. Put a length of tape along the entire leading edge of the wing, folding it around the leading edge (so half the tape is above the leading edge, half below). put the tape at double thickness from about the quarter mark and three quarter mark to the nearest wing tip. Try and make sure the tape is as smooth as possible against the wing, but it doesn't have to be perfect so don't stress. The purpose of this tape is to give the wing tips a little more stiffness. (see picture below)
   
3. On the trailing edge of the wing do the same thing, except also put a double layer of packing tape of length about 20cm centred at the middle of the trailing edge (as in near the propeller). The purpose of this tape is to stop the propeller cutting the wing in the event of a crash under power, and the wing dislodging and obstructing the propeller. (see picture below)

The blue lines show a single layer of tape along leading and trailing edge. The green lines show where a second layer of tape should be applied to the wing edge in question.

Flying It

Although it may not seem it at first the EF is really easy to fly, and it will come to you with time. The transmitter is setup in mode 1 for a three channel meaning throttle is up down on the rhs, rudder is left right on the rhs and elevator is on the left hand stick. On a mode 1 airleron plane airlerons are on the rhs, and rudder is on the lhs.

There are plenty of sites on the internet about how to do your first flight if unassisted so do have a look around, or better yet, get someone to help you. However, I will say just these few things:

1. If you can, practice on a simulator first (FMS and the Vortex extreme model) using a control layout similar to your transmitter (for example, a playstation style controller).
2. Be patient and wait for a calm day. If it always seems to be windy go either early morning or late evening (here in Canberra early mornings are usually calm).
3. Make sure you have a big area (at least a large cricket field).
4. Get plenty of altitude straight from launch (so try to plan to make sure you don't need to turn for at least 50 metres or so from when you first launch the plane).
5. Plan to fly a four sided circuit either turning all left, or all right.
6. Once you have the four sided circuit down, fly a figure eight - away from yourself, turn slowly round to right, toward yourself turn slowly towards the left.
7. Try and find the 3/4 throttle position - I know you have a lot on your mind but at 3/4 the plane wont climb out of sight, nor lose altitude alarmingly - it will be one less thing to worry about.
8. If you get confused about whether you need to turn left or right, just do a small rudder input, and reorient yourself based on the result. Plan your turns ahead of time so you have time to figure this out if necessary.
   
9. When it comes time to land give yourself plenty of room for the approach - anywhere above 10 metres give the plane a *little* down elevator and cut the engine. Hold the elevator ever so slightly down (push up on the stick) and concentrate on keeping the wing tips as level as possible. For your first landing it will be easier if the plane is going away from you, so you don't lose orientation. When you are about 50 cm from the ground if you are losing altitude too quickly then just let the elevator go to neutral - the plane will zoom a little, and probably do a small stall, but don't worry - in this thing at this altitude it wont do any harm. If the rate of descent seems okay then just hold the elevator until the plane kisses the deck.
   

You will learn more finesse with landing as you fly the plane more. The important thing - keep the wings level, and get the belly on the deck at a reasonable rate of descent before you run out of "runway". My experience, which seems to be shared by many is that first time pilots overshoot their landing and tend to end up in trees on the side of the oval.

Once you are more confident you will find the EF can be quite an aerobatic plane (at least, given its status as a "trainer"). More on that below.

Aerobatics

** Before attempting any aerobatics make sure you have plenty of altitude and are clear to fly in any direction that you might find yourself in after attempting the manuveur.**

Stall Turn

Being a rudder plane the EF wont victory roll. Instead, the plane, once it passes a certain roll point, will stall and fall away. This is easy to do intentionally as well, and is a nice way to perform an approximately 180 degree change of direction provided you have *enough altitude*. Simply push the rudder to one side until the plane stalls, then a little up elevator to restore level flight. Make sure you are at least 40 metres of the ground until you understand how much space you need to recover from the stall.

Loops

With its nice big 380 class electric engine the EF can loop pretty easily. Get some altitude, push down the nose for a little extra speed and with full throttle pull back on the elevator. Over she goes. Note - if you are using the mildest control setting (outside hole on the control horn) you might find that this does not work and you simply stall.

Hammerhead Stall

From level flight, at altitude, pull up until the EF is climbing vertically and cut the engine. When the plane falls away give some engine and use elevator to restore level flight.

Snap Roll

Normally rudder planes can't roll but there are two sort of rolls you can do. To snap roll you need a full battery, plenty of altitude and enough space to recover afterwards and reorient yourself with where the plane is.

Push down for speed. Pull up for altitude. One moment later give either full left or right rudder. Hold the controls until the plane has rolled and then reorient yourself to get control.

Barrel Roll

This isn't a real roll, but it does look a bit like it. Set yourself up to do a loop. At the apex of the loop (when the ship is upside down) take away the elevator, and give her full rudder input. If you get the timing right the plane will flip over to be flying the right way up.

Flying inverted

I don't think it can be done, but others have said it can. If you want to have a go then get *plenty* of altitude. Start a loop, and at the apex give full down elevator (opposite of what you where just doing). If the loop was square the EF will "fly" (where fly is losing about 2 metres of altitude per second at least) upside down. However, remeber that to get out of the inverted position you will probably need to finish the loop, and so you need to pull out of the inverted position nice and early to make sure you can recover.

Hop Ups

You have had your EF for a little while now and you think you now have control mastery, and are looking for other ways to push yourself and the EF.

Here are some suggestions - I can only speak to one of them. Others are stuff I have heard people talking about, or seen, but not tried myself.

Bigger Battery

Get yourself some better batteries - ones with a higher mAh will give you a longer flight duration. However, another nice simple upgrade is to purchase an 8 cell 9.6 NiMH pack, rather than a 7 cell pack. The extra poke of 1.2 volts makes a surprising difference to the flight envelope on this plane.

I have found some super cheap batteries - Wincase 1100mAh 8.4 and 9.6 volt NiMH batteries. They are less than $20 a battery shipped from this fellow:

http://www.doublel.com.au/

If you are worried about how the speed controller and engine handle the 9.6v NiMH I can only report no ill effects for my bird. She must have done 25 flights on a 9.6 v pack now (mixed with 25 flights on an 8.4 v 1100mAh NiMH pack) and well over 50 flights on the stock NiCads. There is no sign of premature wear at this stage, but of course brushed engines do wear out, and they wear out faster if they run harder. But at $5-10 for a replacement, it probably isn't worth worrying about.

Increase Control Surfaces

The EF has quite small control surfaces. This suits its gentle handling trainer nature (although it is reasonably responsive on the closest hole setting). A change many people try is increasing the size of the control surfaces. There are tons of ways to do it. An easy way is to just use some of the steel filing pins (the sort that push through the hole with two spikes that then spread out to secure two pieces of paper together) and some business cards. More elaborate changes can be made using depron, or cardboard from pizza boxes - whatever.

I never tried this although I got half way to doing it. In the end I moved onto other planes, although I still fly and enjoy the EF. I think the EF has pretty good rudder authority but could use a slightly bigger elevator.

Motor Upgrade

So, some masochists seem to like to put brushless setups into their EFs. I've never seen one in the flesh but plenty of people post about them online. If anyone has a suggested brushless setup perhaps they could post a comment for me.

Airleron Installation

I've seen people ask about this once or twice on forums. I don't think it could be done without significantly changing the plane. One beauty of the EF is that it's uncomplicated wing is tough because it is simple, and cheap to replace if the worst happens. I would think that to make this mod you would need to flatten the wing tips (to reduce the dyhedral), possibly wing mount some servos, cut the foam and hinge it for the airlerons, get a Y-Cable for the wing servos, and I think after doing all that you would probably find out that you are pushing beyond the little EF receiver's abilities, and that the plane periodically turns itself off whilst in the air.

Whatever you ended up with wouldn't fly like an EF in my opinion. Go and buy yourself an airleron trainer plane instead.

Other Resources

Some other places for good EF and first flight content.

The definitive source of content for the JP Electrafun (not the XP, but still useful):
http://www.electrafun.co.uk/

Electrafun Mods from an aussie - once again not the XP (so throttle mod for example is not of any value) - including some notes on good brushless setups.
http://www.users.bigpond.com/webspace/plms_spad&mugi/electrafun_mods.html


I wrote this checklist for Electric Flight - you might find it handy:
http://www.ozrcflying.com/2007/01/checklist-for-electric-flight.html

My First Delta

So, my significant other gave me a new Windrider Elebee for Christmas, which after spending a few hours on yesterday, and the day before, was ready for its first flight this morning. I was suprised at the amount of weight it required to balance it, but after having read a review on the web where 3 ounces (about 85 grams) was required, I visited the hardware shop and returned with a stack of washers and other steel objects to try and move the CoG.

The Red/Green colour scheme has meant the nick names "Santa's little helper" or "The Polar Express" are likely to stick. It is worth me noting that I didn't get much choice on tape colours.

First launch was a bit of a disaster. I threw her up, opened the throttle. It squirreled around for a while before ending up in the ground. I didn't get the throttle closed early enough and snapped a prop as a result. Fortunatley, there was a spare (although I had to drive home to get it - grrr).

Put her up with the new prop - she was trying to put her noise in the air. I dialed in some down elevon (I had her trimmed for some up elevon based on advice, but I probably had too much). Once I got her trimmed she was flying quite nicely.

It really was too windy, and she was getting blown about a bit by the wind (which was gusty as well as strong). However, I was able to flying the length of the field a few times. On the runs before the wind I reckon she was doing 80km/hr at least (on brushed 400 and 8.4v NiMH).

I tried a landing on the first flight - killed the throttle and pushed her towards the ground, pulled up when I realised she was too steep - pulled up too much, then she stalled and had a moderate nose in - no harm done - indestructible.

On the second battery (a 7 cell NiMH) I was once again struggling to control her in the wind, but got up and down the field work before coming in for a moderately good landing. Thinking the battery still had enough poke I put her up again and flew too more laps before detecting the battery starting to fag out. I knew I was going to struggle to turn her around to land with 1. No Battery to speak of, and 2. No altitude to speak of. Sure enough, when I tried to turn her back to me the lower wing stalled and she spiralled into the ground.

So, what can I say - Deltas are fun, twitchy, but fun.

More news next time I guess.

Confidence

Confidence is an interesting part of human psychology no? As I sit here with the foam safe CA healing the wounded fuselage of my zero I can't help wondering what it is about confidence, and how it is an evolutionary trait, that on the same morning that I did a perfect landing with the zero (really - my best landing ever - was able to taxi straight out to take off again) I also nosed it in trying to do an outside loop in low rate from an altitude that I should have known would always end in tragedy.

The accident, which could have wiped out the plane, has only done a modest amount of damage really considering it was basically a nose in at full tilt. What I'm trying to understand is why I didn't pull out when I realised she wasn't going to tuck under, why I wasn't in the right rate (high rate) and many other things.

At the field I thought the only damage was the fuselage, which was basically snapped through about half way across the wing, all the way round - the velco equiped canopy was what was holding it together. Seemingly no damage to the gearbox (phew), engine (phew) but the prop was smashed. Now that I have her home I see the prop shaft is also bent, so no flying the zero for a little while.

So, what possessed me to try such a brain dead manuveur at such low altitude, and in low rate no less. I have a bit of a fascination with the outside loop. It all comes back to how this bird flew when I first got her. With the little 350 power plant she was quite nimble and could do the outside loop with a 9x7 prop. But her weight wasn't well distributed and she tended to snap roll. When I previously bashed this plane up good through my own stupidity I put in a 400 engine/gearbox combo - the extra weight moving the CoG forward, but also - bigger engine - better performance - right? No it would seem. I haven't managed to do an outside loop since - hence I have made it my benchmark for performance.

Anyway, the glue is dry now and there are more repairs to make. Overconfidence got me here to some extent, confidence will get me out of here.

In case of emergency...

It is always interesting to learn that something you have been told is unlikely, and hard actually turns out to be easier than expected. Such is my new appreciation of whether or not it is possible for model aircraft to collide.

Yes - mid air collision between a mate's electrafun xp and my GWS zero. Now to be fair, I was trying to track him in the zero - to see if my newly timed brushed motor had given me enough poke to keep up with him (It hadn't, but he was running 9.6 rather than 8.4 volt packs) and because it is a great way to challenge yourself. But there are limits.

In the end the problem came when I turned inside him, leveled, and he came up behind me. It seemed like he had just clipped the rudder and the EF flew on just fine. But it was immediatelly obvious that there was something wrong with the zero. Three seconds later my carefully timed electric engine stopped spinning - dead stick. Fortunately every other control was available and I made a reasonable fist of a dead stick landing.

He continued to fly the EF and I checked the Zero's engine. Seemed like the engine had seized but I had no idea how this had happened given that the only contact seemed to be the rudder clip.

Later his EF was landed and we noted a 3 inch cut in the EF's wing - it didn't slice anything off - just a clean cut through the wing like a scalpel. Okay - so the Zero did make contact with the engine/prop - maybe enough to knock the engine out of time, and hence the seizing. Most importantly (well, not really) - the EF didn't escape unscarred from the encounter!

Back home I tried to adjust the timing again on the engine. By brining it back a mm or two I freed up the engine and it spun with about the amount of resistance I would expect. Put the engine on power - good speed - in fact possibly a better timing point than what I had originally. Put a drop of super glue on the engine can to hold it in place.

Flew the zero again today in some appalling winds - it flew really well with the retimed motor, so it would seem no harm done. Met another guy flying at Curtin this morning and he told me a brilliant piece of advice about the TigerMoth - use a coke bottle bottom as a replacement cowling - super idea - I might look into setting it up over the next few days.

Can't wait to see what my better half has gotten for me for Christmas...

We're losing a lot of props

I continue to endeavour to improve my landings with the zero. However, my powered landings are taking a pretty heavy toll on propellors (particularly the three blade props I have been using recently). On average I am getting about 6 landings before I snap a blade.

There are two parts to the problem. The first is that the undercarriage of the zero doesn't give much clearance when it has a biggish (9x7) prop on. The second is that my approaches still aren't exactly correct either.

I've been trying very hard to change my landing technique based on some advice received on the weekend - throttle controls rate of descent, attitude controls speed. So, you use the elevator to give you speed and bleed of speed, whilst leaving the throttle set to continue descent. This is a tricky thing to master. Although there are many things about the plane to learn my actual flying of it is OK (in my opinion) but landing it remains a vital skill, and something I am not nailing everytime (in fact I only nail about 1 in every 4 landings, 1 is okay, and 2 normally involve at least a nose over).

On the weekend I went out to take a look at the Namadgi Sports Flyers Club. Was an interesting visit and was made to feel welcome. So, what has changed and why did I visit - I'll save that for my next post.

Zeroing In

So, I now think I have the zero sorted out although I may not be able to resist the urge to do some more tweaking.

So, here is a summary of what has been done, and what effect it has had:

- Painting underside of wing white to try and improve perspective on plane - worked (still difficult at distance so need to pay attention, but it does stand out a little more, and in my opinion that plane looks better too with those red spots on white wings)
- Upgrade to EPS400 Class Powerplant - after the nosing in the Zero when losing perspective on it, rather than replace the EPS350 gearbox (which was smashed up good) I put in an EPS400. This helped move the CoG a little forward, but was "useful" weight because it's a bigger engine.
- Finally have decided that for both the EPS350 and the EPS400 the 9x7 is the best prop.
- The tracking issue through loops has been fixed by using some double sided foam tape (with the backing left on one side) to push one of the wings down slightly so that its angle is more like the other wing (Thanks Paul@nitrodude).

Getting in heaps of flights with the zero. Landing her on rough grass results in nose over even when you do a good landing unless you are quite lucky. All the same, am getting the landings much much better.

In other news installed the servos and control linkages for the RV4 - she is getting very close to being ready to fly. Had a long chat with Paul yesterday about power plants. Looking at either brushed 400 or some kind of lightweight brushless system. Both have disadvantages.

Later.

The winds of change

Okay - that title merely reflects the fact that today's flying involved quite a bit of wind.

I think I have found the best prop for the Zero. It's a 8060. The engine runs at quite high RPM (even on the 2s LiPo) and I'm getting more like that classic warbird performance - quite a bit faster, but slow to accelerate. The take off run is now around 5 or 6 metres.

The shorter prop also means I am having less trouble with the prop strikes both on landing and take off.

I did 4 takeoff and landings with the zero today. 2 of the landings I'll call crashes - nose over when I first touched the ground, but the last 2 I'm calling safe landings despite what happened. Let me explain ("Here we go," I hear the readers think): The last two landings with the zero were both good. I got the wheels on the ground nicely, had the plane well settled - definitely good contact and rolling along the ground. Closed the throttle and as the model rolled to a stop the wheels dug in and it nosed over. On the second of these the speed at which it nosed over was so low that it ended up balanced between the landing gear and the prop shaft with its tail sticking in the air. Not sure what I can do about this given the somewhat rough nature of the field. Anyway the zero is tough enough to deal with these little nose overs, so as long as long as I can get the landings to the point where I get it right save the plane noseing over as I decelerate I think that is good enough.

As per advice from others am landing the Zero with some power. Gives you a better glide angle and makes flaring safer, and less of a "get it slightly wrong and you crash" activity. I have a feeling the one downside to this is I am landing at a higher velocity than I might otherwise, but that's okay. I don't think it would make much difference to my nose over problem.

Put the electrafun up for two flights on the NiCd cells. I gave both of these a good conditioning last night. One I am quite suspect about - I think it may have dropped a cell. After three very gentle discharge-charge cycles it was better, but seemed to only have enough power to just hold the EF in the air. However, the other one benefitted tremendously from its one cycle and flew like champ and gave good flight time. Had a problem with the engine arming button after that so didn't use either of the NiMH.

Digging In

Well, the Zero is proving to be quite challenging to land, and I must admit I am not rapt in the way she flies with this new engine and prop combo. She pokes along at about 2 knots over stall speed, but she can do that speed at an attitude between 30 degrees up and down. A classic, big, slow flyer prop (1060). This causes two issues:

1. She just doesn't fly the way I want her to, in that classic warbird dive on the allied fleet and give em the full 9 yards, climb away sort of way. For example, at the field this morning she couldn't even handle an inside loop - she just didn't have enough starting speed despite the torque of the propellor.

2. When she is in the rotate position the big 1060 clears the ground by around 1 inch - less that the length of a lot of the grass on the fields. She often noses over on takeoff, and she is nosing over all the time on landing (and I don't think it is all my fault).

So, I'm going to try and find a better sized prop for her. I have a couple in the toolbox - an 8060 and a 90??. Might wonder down to Nitro and see what Paul thinks today.

The Electrafun is back in the air. Went to replace the receiver yesterday and realised that it had detached from the side and was lying next to the servo. Weird eh - the Receiver in the EF lives about 1/4" from the ESC, but that doesn't seem to bother it. Lie it next to the servo, and all sorts of bad things happen. Guess there is a lesson in that.

Have been doing most of my flying at Curtin oval. It is massive, and apart from having to share it with golfers on weekdays, it is basically unused during the week. Is two baseball diamonds and a cricket field. And across the stormwater drain is another area you could fly over (although be careful of the power lines which are not obvious at distance). Maybe I'll do a little post about the local fields I think are good/bad, when to use them/when not.

The Hangar

So, what does OzRcBoy have hiding in the hangar:

Planes that aren't here anymore might be on the Roll of Honour.


GWS Tigermoth 400



Type: 4 channel slow flying biplane
Engine: 400 Class Electric
Battery: 3s 11.1v 1500 mAh LiPo
Avionics: MKS Receiver, 3 x Eflite Servos, GWS 480LI Speed Controller
Built Time: 20 hours
Flight Status: Ready for Flight


Pros: Can fly quite slow and is fairly aerobatic.
Cons: Wing setup is not robust so any hard landing generally requires significant repairs. Undercarriage is a joke.

Build Tips: Avoid using too much glue particularly in the rear of the plane. This one can easily come out tail heavy. Mine doesn't fly that slowly because she is too heavy - be careful.



Stevens Aero RV4






Type: Balsa Kit Low Wing Electric Trainer
Engine: TowerPro 2808-21 13A Brushless Outrunner
Battery: 11.1v 2200mAh LiPo
Avionics: JR R770S Receiver, Hitec HS-55 Servos, TowerPro Mag 8 18A Brushless ESC
Built Time: 30+ hours
Flight Status: Ready


Pros: Kit build great - almost snaps together - just wick in the thin CA. Seperate wing servos makes a flaperon setup doable provided radio supports it. Model flys like it is on rails, even at low power, and zooms on high power (around 130-140 Watts of Power).
Cons: Takes a long time to build. Dihedral means not fully aerobatic. Quite fragile - it can handle a rough landing, but it needs to be a landing. Touch a wingtip and you will go home with pieces.


GWS Zero




Type: Foam Low Wing WWII Scale Warbird
Engine: eWatts 1500kv 16A Brushless Outrunner
Battery: 11.1v 1200mAh LiPo
Avionics: MKS Receiver, 1 Multiplex Nano Servos (airlerons), 2 cheap no name servos (elevator, rudder), eWatts 18A Brushless Speed Controller
Built Time: 12 hours so
Flight Status: Ready to Fly - engine has vibration.


Pros: Cheap, looks great, tracks pretty well, quite aerobatic, quite tough (not Electrafun type tough, but tough nevertheless). Really does rock n roll on the 3s LiPo - almost unlimited vertical.
Cons: Doesn't build exactly straight but can generally be trimmed out.

Built Tips: The angle of attack on the lower wing is too high. You need to move the wing mounting point down somewhere around 3-6mm. If you don't do this your Zero will just climb and climb under power. With the change it will still climb, but at a more reasonable rate.



Windrider Ele-Bee (aka Killer Bee)



Type: EPP Foam Flying Wing
Engine: 2000rpv Himax - rated at 200w - handling about 430w in this application.
Battery: 4s 2200 mAh LiPo .
Avionics: Feiago Receiver, 2 x Hitech HS311 Standard Servos, 35A Align Brushless speed controller
Built Time: 6 hours
Flight Status: Grounded - tape hinges giving way


Pros: Fast (faster than a Styrker C), nearly indestructible, can fly in very high wind.
Cons: High Cornering Stall Speed (which is typicall to all Deltas). Not terribly pretty. Like all Deltas have good performance but can become old quite quickly.

Built Tips: The suggested CoG is way too far forward. Aim for about 7.5 inches from the Leading Edge for first flight, moving it back to around 8 inches once you have tested how the plane flys.


Ultrafly P51 Mustang



Type: 6 Channel (retractable undercarriage) foam warbird.
Engine: FRIO 10 Brushless (included with kit) - 160 Watts on 3s
Battery: 3s 1500mAh.
Avionics: 3 x Hitech HS55 Standard Servos, 3 x cheap no name, MKS Narrowband Receiver, Hobbywing 25A Brushless ESC with Separate Switching BEC
Built Time: 30 hours perhaps
Flight Status: Ready to fly


Pros: Park flying warbird wth retractable undercarriage and a brushless motor included. Foam kit is good quality and all the parts lock together nicely (better than GWS foam warbird for example)
Cons: Heavy, particularly if you plan to use 3s2200 mAh packs. Retracts are a joke (but works okay with GWS ones). Quite a long build.

Built Tips: Don't bother with the Ultrafly Retracts - they are no good. GWS make some micro ones with steel spring wire - these are doing the job for me. Don't bother with flaps - they don't make enough of a difference and you are better off saving 15g. Do whatever you can to save weight. Although the maker says you can go up to 650g that producing a wing loading of a massive 18.1 oz/sq ft - aim to try and keep weight to under 610g and you will have a much more manageable aircraft. I'm using some 1300mAh 3s batteries just to keep the weight low.


Microseether



Type: 600mm Balsa pusher prop Delta - kit build.
Engine: GWS 2205 Brushless
Battery: 2s 450mAh.
Avionics: Towerpro SG50 servos, Align single conversion RX, GWS 15A Brushless controller
Built Time: 12 hours over 5 nights.
Flight Status: Busted

Pros: Small, cheap, novelty value.
Cons: Hard to launch, tricky to keep in the air.

Built Tips: Like the instructions say take your time. Read the instructions and look at the picture before you glue things in place. Make sure you give plenty of up elevon (a little more than the usual delta).

Stevens Aero lil' squirt




Type: Balsa Kit Indoor Electric
Engine: GWS LIPS (Light Indoor Power System)
Battery: 7.4v 450mAh 15C Elegance LiPo
Avionics: MKS Propo 7 channel RX, Towerpro SG50 Servos (5g) x 2, GWS 100 Esc
Built Time: 8 hours
Flight Status: Busted Speedie

Pros: Nice fast build - simple model. She took a couple of hardish landings quite well.
Cons: Maybe too much dihedrayl - I spose it is an indoor "trainer" though.

Built Tips: Don't worry too much about whether your wings are straight until you have covered them. I haven't used any really lightweight parts so mine is a little porker at about 120g (about 50% over recommended weight). If you are this far over you must get the CoG right in the middle of the range otherwise she will snap roll (yes - even with dihedrayl) - obviously not all the way over, but enough so you wont be going the direction you need to.

Ewatts P38 Profile



Type: Foam Profile Kit
Engine: 2 x Ewatts 1800kv 160watt Outrunners
Battery: 2 x 3s of some sort.
Avionics: 2 x Ewatts 18A ESC, rest still to be figured out
Built Time: 5 hours so far
Flight Status: Still needs engines installed.
Flights: 0

Pros:
Cons:

Built Tips:

GWS Mini Dragonfly




Type: Fixed Pitch Electric Helicopter
Engine: 300 brushed can motor
Battery: 2s 1300 mAh LiPo
Avionics: GWS Nano 6 Channel Park Flyer RX, 2 x Esky Micro Servos, GWS PHA300 ESC/Mixer/Gyro
Built Time: 1.5 hours
Flight Status: Ready


Pros: Cheap and tough.
Cons: Like most micro helis strongly affected by its own propwash. Undercarriage and battery tray are pretty awful.

Built Tips: Get some superskids. You wont regret it. Use a 2s LiPo like these ones from PLD.

Stevens Aero G300 "G-Ride"


(not mine)

Type: Balsa Parkflying Aerobat
Engine: Still to be decided - probably an ewatts R2212 or R2822 (1500 or 1200 kv)
Battery: Probably in the range 3s 1200mAh
Avionics: Still to be figured out.
Built Time: ??
Flight Status: Airframe built up but not sanded/covered


Pros: ??
Cons: ??

Built Tips: I'll let you know when I do.


Multiplex Easystar



Type: 3 channel foam trainer.
Engine: HXT 2835 2700kv Inrunner with a 5.5x4.5 APC
Battery: 3s 2200mAh.
Avionics: 2 x VS3 16g servos, MKS Narrowband Receiver, Tower Pro 30A Brushless ESC
Built Time: 4 hours (including soldering).
Flight Status: Ready.

Pros: Flys better in the wind than you would expect a trainer to. Excellent elevator authority. Like most things - a big enough motor helps significantly.
Cons: Rudder could be a little bigger. Easy enough to extend with a business card I suppose.

Built Tips: The two reported problem areas for the plane are wings (when setup for high speed) needing more reinforcing, and the canopy catch mechanism not being much chop after one or two hard landings. I did reinforce the wings, but can't report any issues with the canopy catch mechanism at this stage.
For really high speed work, some rare earth magnets to stop the wings from separating in flight is a pretty good idea.

T-REX 450S



Type: Aerobatic Collective Pitch Electric Heli.
Engine: Align 430L 3550 Outrunner in a can.
Battery: 3s 2200mAh 15C.
Avionics: Align 35A, HS65 Servos, Align RX , HLG200 Heading Hold Gyro
Built Time: I paid someone else to do it (how slack is that).
Flight Status: Ready for flight.

Pros: Seems steady to fly. Nice looking machine.
Cons: Remains to be seen whether steadiness is deceptive. Battery drain is faster than expected (used a 2200mAh just adjusting her for flight, and a short 30 second hover afterwards).

Built Tips: More of a flying tip - adjust your throttle/pitch curve to give you plenty of head energy before the blades start biting. Big thanks to Jeremy who put the machine together and Paul from Nitrodude who helped me do the final adjustments and test flew her for me.


Twister Hawk (Blackhawk)



Type: Indoor counter rotating Electric Heli
Engine: Two brushed motors.
Battery: 2s 800mAh.
Avionics: All included (TX as well)
Built Time: Maybe 15 minutes.
Flight Status: Ready.

Pros: Flys out of the box. Fairly stable. Reasonably tough. Good for keeping dogs and cats in line. The aussie army livery is a nice touch.
Cons: Perhaps not as stable as I expected. Heading hold not as good as I expected.

Built Tips: Um - throw away the box when you are done.

Minium Cessna

Picture coming sorry.

Type: Indoor 3 channnel scale.
Engine: Very small brushed motor.
Battery: 1s 70mAh.
Avionics: All included (TX as well - 2.4Ghz)
Built Time: 0.
Flight Status: Ready.

Pros: Flys out of the box. Fairly stable. Reasonably tough.
Cons: Bit annoying that the TX throttle has no rachet, and that the throttle only engageds from mid point to top throw.

Built Tips: Um - throw away the box when you are done.

Easybox II



Type: Indoor 3 indoor.
Engine: 16g brushless outrunner.
Battery: 2s 450mAh.
Avionics: Hitech RX, EM3.7g Servos, 12A Towerpro ESC
Built Time: 10.
Flight Status: Ready.

Pros: Nice simple balsa build (would be a good first balsa kit). Can be built light, flys well. Goes together fast (one evening is all you need for fuse and wing if you are using thin CA).
Cons: Trailing edge is a little tricky to sand. The wing is strong enough for flying, but some of the load created while sanding it to shape is a bit of a challenge.

Built Tips: See my EBII review for notes on how I did it. One tip I would suggest - sand the Trailing Edge to shape before you glue the wing together.

First Sortie

Well, I resisted the urge to fly the Zero yesterday, as when I arrived at the oval at lunch time the wind had picked up. I chucked the Electrafun up, but it now has some kind of receiver fault. After two landings under trying circumstances the Electrafun is now grounded until some radio issues are sorted out with it.

However, this morning I gave the Zero its first sortie. At Weston oval it was quite still. I did my checks - this was the first time I had used my new JR x2610 transmitter and receiver. I had dual rates and exponential dialed in for the zero and had her in low rate position for take off.

I pluged in the 7.4v 1250 mAh LiPo pack, looked around again, took a deep breath and pushed on the throttle. She was airborne in about 2.5 metres - I guess pushing 10A into a brushed 350 class engine is quite a bit of juice. She immediatelly began climbing, way too much - climb - stall - climb stall - climb stall, I was struggling to keep her in the air, at one point narrowly missing the light posts for the skate park (no one was at the skate park - I should mention that). Pulled the throttle down a bit and trimmed in some down elevator, and suddenly she was behaving quite nicely. A little bit of airleron trim, running at about half throttle and she was going up and down the field quite gently.

She seemed very responsive to me, even on low rate, and I didn't dare change her up to high rate. I tried to little tricks - a loop, no problems although the elevator not being exactly square to the wing means she doesn't track exactly cleanly through that manuver, and a victory roll, which almost saw me in the ground because she took longer to roll than expected, and lost a lot more altitude. When I say close to the ground, think maybe 5 metres by the time I pulled up - closer than I would like.

Had her running up and down the field quite casually - by the end I felt pretty confident with her at only 10 metres or so.

Worrying a little about battery life I sent her to the far end of the field for an approach. The first approach was way to low, I gave some power and circled back around. Second time, got the wings level, power off, dove for airspeed, flared - flared her about 1-1.5 metres from the ground, and then gently pushed her down closer closer til she kissed the ground, still moving reasonably quickly. She rolled to a stop - a near perfect landing. I was just short of shaking on the adrenaline scale. She took some effort to keep in the air but she landed beautifully. Correctly trimmed she tracks straight and true at half throttle, and climbs slightly at full throttle.

This is going to be a very rewarding plane if I can keep her safe I think.

I'll post some pictures shortly hopefully.

The RV4 is still coming - waiting on some hardware to finish her up.

Spending Spree

Well, I took the plunge and stepped up to a proper radio setup. Visited Nitrodude, after bothering Paul with near daily visits every day last week and purchased a JR x2610 radio package including - x2610 computer transmitter, JR Crystall-less 6 channel receiver, 4 Hitec Micro Servos (a swap from the actual Mini Servos that come with the pack), flight pack (for unpowered or nitro powered models) and charger.

The radio is 6 channel, has 10 model memory, tons of functions for planes (elevon, flaperon, delta V mixing, exponential, dual rates etc) and helicopters (don't know what most of these mean so will leave blank for the moment). In the end when with the x2610 rather than the lower speced JR Max 66 because of the helicopter options, and expanded memory.

Also picked up a new plane - GWS Zero - at $89 I think it could almost be called disposable, and I have the spare servos from the TM sitting around at the moment. Spent the weekend putting it together (not all of it, but quite a bit). Has gone together much better than my first GWS model. A very important part is that the model balances correctly without any extra weight. I used the GWS glue to put the fuselage halves together, and a few other things, and used foam safe CA for most other stuff (to keep the build time down). Is nice and light and strong. Although foam safe CA is a bit pricey, provided you don't use it for the major jobs (like joining fuselage halves together) you don't tend to use that much, it is nice and light and strong, and unlike the GWS glue sets in seconds rather than hours.

So, the zero is built, still not maidened. I'll post some photos of it a bit later (in fact, I might post some photos of all the planes.

RV4 Progress

Well, the Stevens Aero RV4 has entered into the closing phases of construction. This phase may take a while because of the large number of components I need to finish of.

All of the components are assembled, and I have started the final sand, and will hopefully start covering in the next day or two (maybe tonight depending on how things turn out).

The SA kits use "pull/pull" setups for the elevator and rudder, which is different to what I have seen - the "push/pull" model using a stiff piece of wire. Pull/Pull uses two thread attached to control horns on each opposite sides of the control surface. These two threads are then tied to opposite sides of the two pronged servo horn. As the servo moves in either direction it will pull one thread or the other, thus making the control surface move in that direction. I must admit it seems a bit fiddly, and I'm not sure why it is seen as better than push/pull. Perhaps it gives you a little more option in terms of running the control lines; a stiff piece of wire needs to run pretty much straight otherwise you get too much friction whereas these threads can curve some. It might also be a bit lighter, but I wouldn't have thought enough to make a difference.

Putting the kit together has been a lot of fun although there have been moments where tiredness, and desire to make some progress has caused some pretty significant mistakes. However, with the hobby knife, and a bit of frustration these all seem to have been recovered from.

Currently I need quite a few things to get it in the air. Probably the most important and expensive is new radio gear. There is no way I am going to fly this on the electrafun gear. The two radio sets I'm looking at are around the $300-400 mark. However, because I don't actually need that all that soon I'm putting it off for the moment.

More pressing things I need to finish up are some hardware like control lines, velcro connectors, an engine and speed controller etc.

I'll keep you posted.

The big crash

While flying last Saturday I had the TM in the air for the first time with a realistic weight, well balanced, a good power plant, and a calm day. The plane was flying well. I'd tried a couple of victory rolls, a few loops and some inverted flying all of which went just fine.

When I had the plane about 50 metres from me I rolled her onto her back for some more inverted flying. She immediatelly began losing altitude. No problem - to be expected, pushed the stick forward and gave her full throttle to hold her up. She continued to lose altitude and put her nose down (so about 10 metres above the ground, upside down with her nose tending towards earth).

No doubt the dreaded radio interference had cut the engine (I was too far away to hear the engine noise), and I didn't realise quickly enough to close the throttle for the necessary 1 second and reopen.

End result, she nosed in for a hard hard crash. Cowling smashed, gearbox smashed, both wings snapped and the upper section of the forward fuselage ripped away from the lower section. A dent was made in the almost brand new 11.1v LiPo pack (worth almost as much as the plane).

I have never had this sort of issue with the Electrafun. Best I can figure, the electrafun 4 channel receivers are dodgy, and can only really do 3 channels well. Anyway, I'm sworn off them for any model which is not somewhat crash proof.

After picking up every piece I could find I glued the TM back together as best I could. It went back together better than expected, and in the end only one small piece of the fuselage couldn't be found. I'm planning to fill that hole with Selley's Spakfilla.

The LiPo pack seems to be okay. It took a charge, is showing no sign of swelling, and there is no indication that the pack has been ruptured. Will keep a close eye on it of course. All the servos, the speedie and receiver seem okay (such as that f*#&$*# receiver could ever be called okay). I might recycle them into a flying wing that I've been looking at down at Nitrodude. The wing is EPP so breaking it is tough, and even if you break it, you just glue the single piece back together, and of course only needs three channels (airlerons, elevator and throttle). Elevator is an elevon mixing setup. This had me concerned - the Electrafun transmitter can't do elevon mixing (where pulling back on the stick actually makes the two airlerons work like an elevator together - each airleron needs to be served by its own servo). However, there is a neato Himark elevon mixing component. You plug it into the elevator and airleron channels on your receiver, and then your two airleron servos into the back of it and hey presto, elevon mixing without an expensive transmitter.

Where Have I Been

No, London was not involved, nor have there been any royal entanglements. However, I haven't been doing much flying recently. But there are some exciting model aviation based things happening anyway.

Firstly, trying to get the Tiger Moth right before I fly it again has been an issue of concern for me. To that end I purchased an 11.1 volt 1500mAh LiPo, because she needs more power based on her portly weight.

I flew her last Sunday morning with the larger battery. With power she flew well, but I had a pretty hard crash trying to land her off power. Her glide decent rate is just too high, and I made the mistake of letting her glide in rather than diving for airspeed and flaring. Was a big acco, and I did a bit of thinking about how to make her flyable, and have put in quite a bit of sim time practicing landings.

One of the things I knew I needed to do was reduce her weight. The heavier LiPo sat basically above the CoG and so wasn't influencing the weight much. To this end I spent about 1.5 nights this week slowy chiselling away at the battery compartment so that I can slide the battery forwards. The battery is now held more securely, and I have been able to remove about 30 grams of weight from the cowling and still get her to balance well.

The other exciting thing I have been doing is building a new model. I'm in no rush to finish it, but it is a Steven's Aero RV4 (http://www.stevensaero.com/shop/product.php?productid=16491&cat=253&page=1). It's a scale replica of the famous RV4 kit plane, which was I believe the first kit built plane to fly around the world. Although I was holding out for a Steven's Aero G300 (G-Ride) discussions with Paul at Nitrodude convinced me this was probably a better plane. It should be quite aerobatic, but just a modest amount of dihedreyl will make it a little more tolerant of mistakes, and the model is designed to fly very well on low power (flys with authority on 70 watts).

At this stage the plan is to use one of the GWS brushless motor/speedie combinations, a big biting prop. The GWS motor/speedie combo is ridiculously cheap (GWBLM001 around $50) for a brushless setup, but can draw 140 Watts for short bursts and 90 Watts for 5 minutes or more. I'm going to use a 7.4Volt 1250mAh LiPo I bought for the moth as the battery, which will mean I need a pretty aggressive prop to draw even 80Watts. An 8040 will go close appraently with this setup. I don't know if there is anything with a more aggressive pitch than that.

Putting the kit together has been scary but fun, and the SA kits are amazing. I've never built from Balsa, but I can't imagine it gets easier than this. All the parts are laser cut and drop out with the slightest provocation. All of the truss components interlock, and the model is basically self jigging. I've been making pretty slow progress, and almost made a project ending mistake, but I was able to free the parts and put them in the correct position.

Progress to date, the fuselage is almost complete. I'm hoping the wings will come together a little more quickly, but I guess much depends on the confidence and speed I proceed with.

I'll try and update the flight log later - off to fly the tiger moth and electrafun.

Interference Continued...

So, the battle to get the Tiger Moth in the air, without interference or problems, continues.

Can I just say the guys @ Toyworld have been sensational in trying to help me track down the problem, have given me plenty of their time and lent me some gear to try and diagnose the problem.

I've been round and round the mulberry bush on this one. Yesterday I finally though I had it figured out after I replaced the Electrafun servos (in the TM) with some cheap replacements on loan from Toyworld.

When I tested it, with the lower wing off (and hence one more servo not in the chain) it seemed good up to quite large distances. But today, when I took it to the field I started getting jitter in the rudder at only 15 yards or so. I put the plane up but the flight did not go well (see flight log) - a reasonable landing was organised given the circumstances with no significant damage but there is not doubt in my mind that the Moth was not responding properly to my control inputs suggesting jitter was making the thing more or less unflyable. Also should note had big throw on control surfaces, but this is something you can compensate for with the transmitter by being delicate on the sticks, and I was. The problem looked exactly like certain control surfaces - rudder in particular - being flicked quickly in one direction.

I'm going to disconnect the airleron servo which wasn't present the other day and see if I get a different result. If I do I think there are two possibilities.

1. The airleron servo is faulty - unlikely, it is new and wasn't cheap.
2. Leading back to a theory we are considering but not currently investigating - the 7.2volt LiIon battery might just not have enough volts to run the receiver, 3 servos and the engine cleanly.

When we do sort this problem out I will try and give you a run down on what (if anything) I have learnt about trouble shooting problems with RC planes.

Interference

Well, many days of not posting - the Tiger Moth was finished, flown, crashed, flown twice well, flown more and crashed.

I am getting radio interference on flying and it is causing big problems with trying to fly the TM.

Here is one lesson I know for sure:

If you cannot do a radio check up to 20-30 metres without getting jitters etc then do not take off. I know you want to fly - I did too, but it will just end badly.

So, I have been trying to figure out what is causing the radio interference.

By isolation I have eliminated:

The servos
The receiver (have switched in a known good receiver)

The remaining possible culprits are:

The crystal.
The engine.
The Speed Controller.

Given the interference is occuring when the engine is not running neither the speed controller or the engine seem likely culprits - after all, they need to be running to be generating significant interference.

Have consulted widely for advice - thanks to the guys at Toyworld and Paul @ Nitrodude. Still looking. I have a crystal on order, so maybe will be able to test that tomorrow if it arrives.

Some notes on the setup for those that want the gory details:

Plane: GWS Tiger Moth 400
Engine: 400 speed brushed
ESC: GWS 480Li
Receiver: 27Mhz set recovered from dead electrafun carcass
Battery: 7.2 volt 2300mAh Lithium Ion
Symptoms: Jittering control surfaces and occasional engine spin ups at 25-30 metres on very fresh transmitter batteris, 15-20 metres on 85% transmitter batteries.

I have had a few good flights with the TM and I love the way it flys - nice and slow, gentle airleron roll in. If I can just get this radio problem sorted I might be able to bring the thing down in one piece each time - it has had a lot of hard landings, and whilst it is not ruined yet shortly it will be more hot glue than foam.

Am also thinking of trying to use some aluminium foil to see if I can shield the receiver from the ESC. The speed controller might prove to be the culprit yet - I have some concern I may have damaged it whilst soldering the connectors for the new battery into place by creating a short on the circuit board. Although I thought I had probably fixed it I didn't have a solder sucker so just scrated a break in the circuit. Opinion from the experts is that if I had shorted the ESC it probably wouldn't work at all, not just have minor issues.

I'll try and update the flight log tomorrow - not looking forward to writing up all my crashes - grim.

New Stuff

Yesterday I bought some new bits from a shop in Kambah called Nitro Dude. They have a website http://www.nitrodude.com.au.

Needed a new battery for the Tiger Moth (probably maidening tomorrow) and also needed a charger given my pissy EF charger (which to be fair has served me well) wont charge anything except a 650mAh 8.4v NiCD it would seem.

So, I bought a Swallow, who unfortunately isn't Robyn. Didn't get the Swallow Two - it was an extra $40 and the I already have a 240v AC/12 DC Supply. And the battery, which is a Lithium Ion 7.2 volt, 2300mAh job. Paul, from Nitro Dude, said that battery will probably keep the moth in the air for about an hour (an hour!). Was a bit overkill for the application perhaps, but it is what he had in stock.

Well, maidening the TM tomorrow I hope.

Introducing the new plane

Well, on Friday I purchased the new plane. After quite a bit of reading and reviewing, and a discussion with the guys at Toyworld I went for the GWS Tigermoth 400.

I've just spent the weekend putting it together. The "Big Moth" is an Almost Ready to Fly (ARF) Kit with an estimated build time is 6 hours, I think I probably took 20 all up, but it is together, and I think it is reasonably straight.

During the building I found something most surprising happening to me..., I enjoyed the building. This isn't something I expected, as I thought all I really wanted to do was fly these things, but building it turned out to be a whole lot of fun.

Anyway, the plane is now assembled but I need a couple of things before I can call it done. I need a new radio crystal (the avionics is mostly kit that I recovered from a dead electrafun carcass (don't worry - the original electrafun is still there and raring to go) for either the moth or my handset. None of the batteries I have are the right shape for the moth, the propellor assembly is not correctly attached, and something needs to be done about the undercarriage. I also need a place I can try flying it, and will ask someone to look it over before we get to that stage as well.

I'll try and post some photos soon.

Checklist for Electric Flight

Here's the checklist I am using. I add to it as I learn things. It starts at the field and assumes you have bought your plane, batteries, controller etc.

1. Safety Check - Assess the field. If there are people using the field make sure you can fly safely with them there. Don't plan to fly over them, plan to fly in the space they are not using. If there isn't enough space don't fly. Come back some other time.
2. Sun and Wind Check - Assess position of sun and direction and strength of wind. Go to a position on the field where you can safely take off into the wind, and wont have to deal with the sun during your flight (so ideally, be near the edge of the field with the sun at your back). If the wind is strong make your own call based on experience, skill and judgement as to whether or not to fly.
3. Sun glasses check - look into the sky for a few moments (say 10 seconds) and figure out whether you need your sunglasses or not - even on overcast days where you wouldn't use your sunglasses at ground level you may still need them due to glare.
   
4. Frequency Check - Check that no one else is flying or using RC in the immediate vicinity. If they are, check what frequency they are on. If necessary wait.
5. Plane Check - Check the plane is straight. Make sure the wings are correctly aligned.
6. Transmitter Voltage Check - transmitter on. Check voltage indication is okay.
7. Battery Connection and Check - Make sure throttle is closed. Connect battery to plane. Check that battery is properly connected by ensuring it wont pull out without using the clip.
8. Control check - standing next to the model operate the rudder, elevator and airlerons (if you have them). Make sure they travel freely and without hinderance.
   
9. Trim check - Check the neutral position of the control surfaces with no control input (ie transmitter on, but sticks not being pushed in any direction). Make sure they align well and adjust trim using transmitter if they don't.
10. Radio Check - with the transmitter on but the aireal not extended, walk 25 metres away from the plane and visually confirm that all control surfaces respond to control input through the transmitter. (Note: Don't combine your radio check and control check - you can't see the control surfaces well enough at 25 metres to be confident they are moving freely.
11. Extend your aireal.
    
12. If you are "taking off" rather than hand launching then do the engine and throttle check (15) now.
    
13. Last Safety Check - look around the field once again and make sure you know where any groups of people are congregating. Once the plane is in flight you will not have much opportunity to look at the ground (because you should keep your eyes on the plane) so if the field is busy consider not flying. Keep in mind people will move about while flying.
    
14. Last Wind Check - Is the wind still coming from the same direction? Is it still safe to fly? If you are "taking off" rather than hand launching, you are clear to take off. If you are hand launching proceed to 13.
    
15. Throttle and Engine Check - Arm the engine (if you have that feature). Holding the model firmly open the throttle gradually making sure the engine comes on when it should, and at full throttle makes the normal noise (you only need to listen for 1 second or so to tell). If you are hand launching then launch. If you are "taking off" then proceed to 13.
    

If you have anything you think I should add then let me know.

More Electrafun Fun

Since learning the roll the other day I've been trying to see what other aerobatics the Electrafun might do.

I have tried:

• An outside loop - not possible in stock trim as best I can see. The wings just generate too much lift and all the plane does is dives almost perpendicular to the ground. I tried it twice and pulled out both times after losing about 40 metres of altitude with no indication the plane was ever going to tuck under.
• Hammer stall - success. Full power, pull back on elevator. Power off, let the plane stall and fall away.
• Flying inverted - success. Make sure you have plenty of altitude, full throttle, dive for speed, pull back and start to loop. At the top of the loop push down (up on the stick) with full elevator. Your Electrafun will "fly" upside down with the fuselage staying horizontal to the ground. However, because the EF doesn't have symmetrical, or even semi symmetrical wings you will lose altitude at a somewhat alarming rate, and the only way you can get out of the inverted position is to pull up with the elevator (back on the stick) and complete your loop so you must leave yourself enough room to do this, otherwise disaster is just a matter of moments away.

I haven't tested what rudder does when flying inverted yet. Watch this space for the results of rudder while flying inverted (will post back in here).

*** Update: Best I can tell, using the rudder whilst inverted just sort of confuses your plane and will make it continue the loop that you started ***

Learning More About the Electrafun XP

Yesterday I was talking about my proposed new plane. Today I am talking about some new things I have learnt with my current one.

After flying with some of the guys from Toyworld and associated hangers on yesterday I was told a few useful things about the Electrafun.

Landing

The Electrafun's smallish control surfaces mean that it is quite sluggish to respond unless it has quite a bit of airspeed. This is good for beginners - the aircraft is a little more docile. However, it does present a bit of a problem when trying to land the plane, particularly if just gliding in (as per the method in the instructions).

By and large the advice from those at the park that had the Electrafun was:

1. Power off.
2. Dive for speed (not super steep, but a dive so you pick up airspeed).
3. Flare when you are quite close to the ground and then use the slightest down elevator to hold the plane at that altitude (its speed will make it want to climb) until the airspeed drops sufficiently and then just use a little more down elevator to push it gently to the ground.

I tried this landing approach this morning and it works much better than just letting the thing glide off power. You are much more likely to get the plane down where you want to. Your own airspeed makes the plane much more stable and responsive. Worked quite well, but maybe is not a technique for complete beginner's (now calling myself an intermediate beginner 8-) because of the finesse required on the controls to pull out of the dive early enough to not plough into the ground, but not so early that you just end up in the horrific low speed gliding thing.

Takes a bit of self control to use down elevator when so close to the ground as well, but the technique definitely works.

Tricks

Learnt a new thing the Electrafun could do yesterday that I didn't think it could. It can do rolls, not victory rolls the way a spitfire can, but something that is not a bad effort for a three channel trainer.

Firstly you need some altitude - I'd guess 20 metres would be a minimum - give yourself 40-50 first time you try it.

1. Full throttle - dive for some extra speed.
2. Full up elevator and almost instantaneously full rudder (left of right depending on how you which way you want to roll)

You need your engine to be running near full speed to pull it off, so attempting on low battery will probably end in disaster.

The plane will flip left to right or right to left (depending on rudder) - not as elegant as a roll in a airleron plane and you need to know that unlike an airleron plane it wont emerge going in more or less the same direction, but instead will tend to deflect 45 degrees or so towards the direction you first steered.

Thinking about it the Electrafun should also be capable of a hamerhead stall.
Modifications

There are a few places on the net that talk about mods for Electrafun's. Here are some of the things considered worth doing by those I spoke to yesterday:

• Buy some good batteries - the EF XP's included batteries are 600mAh, meaning you get about 5 minutes of fullish throttle, and with some coaxing can get flight times or 10 minutes or more if you have a good day for it. You can buy 7 cell NiMH batteries with 1200 and 1500 mAh, which will give you 10 minutes or so on full throttle.
• Make the control surfaces larger. Apparently some sites suggest using old ice cream containers to make extensions for the control surfaces. I am kind of thinking about it.
• Bigger engine. Install a bigger bushed engine, or maybe even a brushless engine (as well as lipo batteries I guess). Will make the EF quite a bit faster, but that would seem to cost as much as the original plane did to buy (certainly in the case of the brushless).

The things I'm immediately considering are buying batteries with more Amp Hours for longer flights, and maybe trying to increase the size of the control surfaces. I spose good batteries will also mean buying a proper charger. This stuff may have to wait a couple of weeks still.

My Next Plane

Have been doing some contemplation over what plane I should go to next. Some of the criteria I am looking for:

1. Something that has a slow flying speed - the field I am flying at is reasonably small (although there is another good oval nearby at Lyons - it may be magpie free - I should check it out).
2. Reasonably rugged and forgiving - meaning balsa kits are probably out - looking at a foamie of some sort.
3. Ready To Fly or very short Kit build time - I'm in the hobby to fly. Building a few things does give me a sense of satisfaction, but I am busy, and I don't have 30 hours to build aircraft.
4. Something forgiving, but with airlerons - The Electrafun is a three channel plane - no airlerons, so it can't roll meaning you are pretty short on aerobatics that you can perform. However, the plane , whilst having airlerons needs to be somewhat forgiving - a super touchy plane will almost certainly see me on the ground in pieces in pretty short order.
5. Something with scale appearance - The Electrafun flys okay, but it is not a pretty plane. My plan when getting into the hobby was to work my way towards some WWII warbird park flyers. That's still the plan. Something that fits in that theme would be nice.
6. A plane that I can reuse my avionics from my dead Electrafun fuselage would be nice - might save me $100 or so on the cost of setting up the plane.
   

I had a chat to the hobby shop based on these ideas. There seem to be a lot of Cessna 182 kits and RTFs out there with airlerons, and it is supposed to be a quite forgiving and stable aircraft. However, most come with a set of radio gear etc - which I already have.

There are quite a few balsa kits, like the Piper Cub, but here the question of ruggedness is immediately apparent, as well as build time.

I'm still considering both these planes - which would be good "advanced trainers", but the one that I am now strongly leaning towards is the GWS Tiger Moth 400 (sometimes called the GWS Big Tiger Moth to differentiate from their pico Moth).

The 400, which is a pretty good scale appearance for the de Havilland Tiger Moth is:

• 4 channel bi-plane with rudder, airlerons, elevator and throttle.
• Foam constructed.
• Comes as a kit requiring about 6 experienced hours to build (so I'm allowing 12).
• Includes an engine, and should be able to use the batteries and spare servos etc from the dead Electrafun fuselage.
• Has quite a low stall speed due to the lift of two wings (so can fly slow).
• According to reports has scale roll in for airlerons, meaning it is not so quick that you flip the thing on its back and it crashes.
• Once mastered can do most all the tricks. In fact with a bigger engine it seems you can almost make it a 3d plane.
• Kind of fits with my theme of WWII warbirds given many allied WWII pilots trained on the TM before moving on to the Spits, Hurricanes, Mustangs and the rest.
  

Having read a few reviews on the web almost every single one is glowing of the 400's flight characteristics, with quite a few people describing it as a good first airleron plane. There were some negatives:

1. The landing gear is flimsy and needs to be reinforced, or discarded. It seems some people are making perfectly happy belly landings and given the roughness of the fields here in Canberra, that might be best for me too.
2. The kit instructions sound a bit average, but there are plenty of reviews of the build process on the web which give guidance in the area where the instructions are not brilliant.
3. It sounds like the wing struts need some sort of reinforcing.
   
4. Some people have reinforced the wings to prevent folding under extreme maneuvers.
5. The glue included with the kit is useless. Use epoxy resin or a hot glue gun was the other suggestion.
   

So, the price of the 400 was around $120 when I checked the hobby shop the other day. I'll need at least another servo, and probably a speed controller as well. Maybe another $60-70 dollars.

Anyway, I've done 27 flights on the Electrafun. I'd this number to be 50 before I take on the Tiger Moth - maybe I'll let myself buy it and start building it at the 40 flights mark.

Blowing in the wind

As time has gone by I have been putting the Electrafun up into breezes really beyond its design more and more. This is a result of a few things. Increased confidence in controlling the aircraft is certainly one of them. The general absence of days that are still enough to fly the Electrafun is another.

However, I probably shouldn't be doing it. I should probably fly some more and get some more experience on calm days.

Here are some of the things I have learnt:

1. Provided the plane is in the air, at altitude it is reasonably safe. Even in a strong breeze if you can keep the plane turned into the wind, keep the nose down (the wind may cause very high wind speeds, causing the plane to climb).
2. When you need to turn the plane downwind, you will get the impressive site of your Electrafun moving faster than you have ever seen it go. I think it might have been up to 100km/hr on one run the other day. The obvious point here is, start your turn back into the wind early. The plane will disappear from your site, or go towards those trees, much sooner than you expect.
3. You need plenty of battery power to fly in the wind. You don't have to have the engine on all the time, quite the opposite to some extent. But you need to have energy to get you out of trouble.
   
4. Further to above, start your landing approaches whilst you still have plenty of power. Patience is the key - simply wave off each approach that is spoiled by the wind, power up and come around for another try.
5. Give yourself more room than usual for the landing approach. The wind will push the plane down, the wind will make the plane soar, the wind will just mess up the whole business of approach.
   
6. Once you are off power on your final approach, expect the wind to try and turn your plane away from it. Anticipate this and give some slight rudder inputs to try and keep the plane steady.
7. Gusts will mean that your plane, in an instant, can go from cruising happily, to stall speed, to the speed where it climbs at 40 degrees. Try and keep the nose down on approach so that even if the wind drops of you don't have a full on stall.
8. Expect less than perfect landings. The most critical things IMO are a) make sure the wings are level, b) try and make sure that you have enough speed to flare and c) if you see the plane start to nose up towards a stall, dive the plane to try and pick up air speed. If the Electrafun stalls from anywhere up to two metres, but hits the ground with wings horizontal the chance of any serious damage is quite low. The important thing is to protect your wing and tail plane.

I haven't tried it, but another useful trick might be to line your landing up with just some slight throttle, ideally cutting at the last instant before touchdown.

Be careful of coming down too low whilst flying. It is easy to lose altitude quickly when the wind is strong (and easy to put it on as well).

If you find yourself caught in strong gusts, my advice would be, keep the plane up nice and high, use as little battery as possible, and just wait for a period where the wind is low enough to land. The chance will probably come. While the plane is at altitude it is reasonably safe.

When Animals Attack (Model Aircraft)

If you have read my flight log you will see that basically every entry mentions magpies attacking my plane (for those not familiar with magpies: http://www.amonline.net.au/factSheets/australian_magpie.htm).

Previously I have referred to them as birds of prey, which is somewhat of an exaggeration. Whilst they are carnivorous (or maybe omnivorous) their usual prey is insects and larvae, although I have heard stories of them stealing and eating young chicks from other birds nests.

The magpie is a sleek, beautiful looking bird with a charming song, and will even accept food from the hands of people. These birds have only one problem - in mating season they become highly territorial and some will aggressively swoop people that near their nest (where "near" can be as much as 50 metres or more).

It is magpie breeding season at the moment, and I'm thinking this is the main reason my plane is being harassed. To try and counter their attacks I have tried a few techniques that do not seem to have had much effect.

I have painted "eyes" on the tops of the wing, on the top of the elevator and rudder. I've painted bands on the propeller (so that when spinning it should look like a complete circle, facing backwards). However, this doesn't seem to have had much effect.

The propeller is the best defense against attacking magpies in many ways. By having it on it stops the bird from seizing the plane at the base of the wings and trying to tear it apart. However, I am somewhat concerned about the harm that might come to a magpie out of these "encounters". Today for example, I was trying to soar, saw a magpie coming in to attack, turned on the engine, but probably a moment to late, the magpie hit the prop reasonably hard and although both the plane and the magpie flew away, and single black and white feather fell to the ground. I was hoping this encounter might have convinced the magpie to leave the plane alone, but it does not seem to have had that effect, as he came back shortly thereafter to sort the plane out.

What I have noticed as flying, is that the area which birds are insisting on protecting is much reduced over when I first flew. I'm taking this as a good sign. I don't think they know how to deal with the plane, and provided it doesn't get too close to their nesting trees they will take a live and let live approach. Also, when they come after the plane, provided the prop is running, they are more interested in harassing and squawking at it, than actually attacking it. A good sign that they have learnt to fear the propeller.

The birds are actually fairly easy to evade once you have some mastery of the controls. They cannot turn as tightly, or climb as quickly as the plane, often leaving them undershooting it and coming back. Of course, once the plane is off power and trying to soar, it is a sitting duck.

At this stage I think my only approach, apart from not flying there, is to try and keep the aircraft away from their particular trees, and continue to evade them as best I can.

PS - today as I was doing my radio check I turned my back on the plane (as it was on the ground with the engine off) and walked away the requisite distance. When I turned back, a magpie was on the ground creeping up to try and cripple the plane on the ground, or at least that is what I assumed. I ran back to stop the bird from attacking the plane. In hindsight maybe I should have let it have a close look - maybe it would have convinced the bird that the plane wasn't a threat. However, I have my doubts. At this time of year magpies don't even approach having a reasonable attitude to other living creatures in their vicinity.

The Electrafun XP

*** Hi there - since I wrote this I have changed my mind about a few of the things I wrote in this post, and have also put together some photos etc to help those getting an Electrafun XP ready for its first flight. Feel free to read what I originally wrote of course, but also take a look at:


http://www.ozrcflying.com/2007/01/electrafun-review.html


Begin original post:

A friend has asked for details about my plane, the Electrafun XP. Rather than answer him directly I though I would put the lot up here for any other interested parties.

The Electrafun XP is a Ready To Fly (RTF), electric powered, three channel aircraft designed as a trainer plane which I think (you know - with all my experience in these matters) is suitable for beginners, particularly if they combine it with simulator time. However, with respect to my notes on this plane and my opinion of it, do consider, it is the only one I own at the moment.

What it costs and what you get

My plane cost around $150 from Super Toyworld in Fyshwick ACT. I've seen the plane advertised on the web down to around $130, but would suggest if you buy over the web you make sure you are buying from a true RC Hobby shop, and that they are in the same city as you, and reasonably close to you.

The Electrafun comes with everything in the box:

1. The fuselage (already assembled, all radio gear installed etc).
2. Two wings (a spare one for when you bust the first).
3. Two sets of tail planes (elevator and rudders) - once again the spares are for accidents.
4. A fast charger.
5. Two battery packs.
6. Undercarriage (essentially useless - don't use)
7. 4 channel radio controller.
8. All the radio gear in the plane - three sets of servos etc - but don't worry you don't need to know anything about them.
9. Manual and a somewhat amusing DVD on how to fly the plane.

The four channel radio set is one of the big bonuses of the kit. That's because the radio set can graduate with you when you are finished with the Electrafun. As it was put to me, the electronics and electricals in an RC plane, represents the majority of its cost. The radio controller, servos, receiver, engine, batteries etc are the greater portion of the $150 odd you pay for the plane. One advantage of the Electrafun over other beginner planes is 1. It really does fly, and 2. You can take your RC gear out of it to an advanced trainer when you are finished with it. This means you next plane will probably only cost $70-80 when you are ready to retire the Electrafun.

Where to get it

I know people hate paying more for stuff than they have to, but seriously, for a difference of $20-30 consider going to a real hobby shop, for a few reasons:

1. The kit quality on the Electrafun can be a bit random. I guess most are fine, but I had problems with a faulty charger, and the tail plane assembly not sitting parallel to the wings. With the help of Super Toyworld both these matters were addressed to my satisfaction (replacement in the case of the charger, being sold a cheap fuselage in the case of the other because I had broken the carbon fibre rod to the tail plane when trying to "correct" it).
2. The bits of advice they give you will be very valuable. I've put some of their advice in this post for example. I wouldn't know it so early in my flying unless they told it to me.
3. Buying from a nearbyish store will give you ready access to spares. This is one of the Electrafun's strong points. New wings, and new tail assemblies are readily available and reasonably priced ($12 and $6 I was told).
4. The hobby shop will be keen to see you in the hobby. They will keep you away from airplanes that aren't appropriate (they should anyway) connect you with others that are doing the same thing. Super Toyworld even run a clinic for first time flyers every week (I haven't been yet, but will try and get there some time).


Putting it together

Once you take the plane out of the box, watch the DVD and read the instructions it will then take you about 15 minutes to put the plane together for the first time. The wing attaches to the fuselage with rubber bands. The tail assembling simply screws into the carbon fibre tail rod. Just connect the push rods before you screw the tail assembly in place and you are done.

Yes, it is that straightforward.

By the way, consider going for the middle position on the control arms. The Electrafun has three positions you can put the push rods into making it sluggish, medium or responsive to controls. The sluggish position is so sluggish I think you will be frustrated by how unresponsive the plane is - this is particularly so if you have some simulator time.

If your model does not trim correctly (you can't get the control surfaces to a neutral position even using the trim tabs on your radio set) then consider just using some pliers to increase the angle of the bends in the control arm - this should move the control surface a little more in the direction you need.

Flying it

The Electrafun XP is a three channel plane. You get control of rudder, elevator and throttle. The controls are placed on the controller in accordance with the normal RC layout.

Left stick:
Up-Down: Elevator
Left-Right: Airlerons (not present on this plane).

Right stick:
Up-Down: Throttle
Left-Right: Rudder.

On this plane, which has a high dihedral wing (meaning the wings angle up from the horizontal, giving the model a self correcting nature) the rudder makes the plane bank. The elevator can be used to make the turn faster as well as maintaing altitude depending on the angle of bank.

If you bank the plane to far, it will go into what is called a stall turn - this is where a rudder plane is different to an airleron plane. The airleron plane will simply fly upside down (and rapidly plummet towards the ground because the lift is acting in the wrong direction). The rudder only plane will stall turn, and provided there is enough altitude, with a little up elevator, recover at the bottom of the dive.

As I mentioned in a previous post your first flight will be an exhilarating and probably frightening thing. Do yourself a favour and get FMS, and the vortex extreme model, a playstation style controller for you PC, and practice flying in the simulator. Otherwise your experience will be like mine, where I was closing the throttle when I wanted up elevator and uselessly pushing the airleron stick from side to side when I wanted to turn.

Prepping the Plane

There are a few things you can do to improve the survivability of your Electrafun. Firstly buy some packing tape - the clear stuff will leave your plane looking nicer at the end of it, but apart from aesthetics there is nothing wrong with the brown stuff either

Put a length of tape along the entire leading edge of the wing, folding it around the leading edge (so half the tape is above the leading edge, half below), and put the tape at double thickness from about the quarter mark and three quarter mark to the nearest wing tip. Try and make sure the tape is as smooth as possible against the wing, but it doesn't have to be perfect so don't stress. The purpose of this tape is to give the wing tips a little more stiffness, not much but just enough to hopefully prevent the wing tips folding in an extreme maneuver. This isn't so much a problem with a pristine wing, but one which has had a buster may have a fold in the foam of the wing, which may result in the wing not having enough stiffness in the air. The tape treatment will help.

On the trailing edge of the wing do the same thing, except also put a double layer of packing tape of length about 20cm centred at the middle of the trailing edge (as in near the propeller). The purpose of this tape is to stop the propeller cutting the wing in the event of a crash under power, and the wing dislodging and obstructing the propeller.

If you have birds of prey likely to harass your plane (magpies for example) I would suggest some additional treatments. Near the centre on the trailing edge (so once again near the prop) use some more tape on both top and bottom of the wing so that there tape covering the wing from the trailing edge, to about a third of the way toward the leading edge. This will probably only take a single length of packing tape for the top and one length for the bottom. This tape is designed to stop a bird of prey from gripping and tearing the wings. I'm guessing a wedge tailed eagle will still make short work of your plane, but for smaller birds such as magpies, this should be enough to stop them from tearing pieces off the wing.

Repairs

Simple - don't crash and you won't need to. Yeah right!

Take your role of packing tape, and get some foam safe super glue and araldite. Although I haven't experienced it with the Electrafun foam and I am told by others that normal super glue eats Electrafun foam - that isn't my experience, but you'd best use foam safe CA like this.

If you brake a tail (as I have, the same tail - twice) then provided it fits well enough together then glue it (with foam safe super glue), hold until it sets and then reinforce the joint with some packing tape. Obviously make sure you don't put the packing tape on the actual control surface (because your controls wont work, or wont work as well as they did).

Araldite, is very strong. In fact I have had the tail snap within 2 cms of a joint repaired with araldite, suggesting that araldite is stronger than the foam. However, araldite is heavy, a pain to use, and smelly. However, it can do a job super glue can't. If you need to fill space you can put a dob of araldite in there. After a pretty hard crash I had the holes in the elevator panel elongated, meaning that the elevator panel would necessarily sit in position. I used araldite to fill in parts of the elongated hole, so that the screw would only fit through were it was supposed to. By the way, don't bother with araldite with hole in the wing. Glue the foam together (if there is any left) and just use tape to give a smooth finish.

Foam safe super glue seems fine for most repairs in my opinion. Remember to back it up with tape over the same area (regardless of whether you use araldite or super glue).

Aerobatics

When you feel up to it, the Electrafun can:

- Stall turn.
- With a great deal of encouragement, and a full battery, can do loops.

That's about it.

Summary

This plane is cheap, its components are reasonably tough and forgiving, can usually be easily repaired, and can be replaced where necessary. It behaves predictably in the air (provided wind is light), and gives you radio and other gear that you can take to your next plane when you are ready to graduate. In fact, it is clear that this plane is designed to draw you into the hobby, rather than just get some bucks of you. My experiences have been good. Feel free to post if your differ.

Simulating Times

When I started investigating RC planes I, being a good geek, of course turned to the Internet looking for information.

One of the first things I encountered was people talking about flying simulators for model planes. And there was some debate over their usefulness as well.

With a bit of investigation I found out there was a free (as in beer) model plane simulator called FMS (Flight Model Simulator). You can get it of my website (as well as some useful training models, or from the FMS homepage.

I downloaded it and had a play. I also found a model for it called the "Vortex Extreme" which was a pretty close fit for the Electrafun (my "real" plane).

On the matter of using a simulator versus not using a simulator I have heard arguments put such as:

1. Just being able to reset a crashed plane doesn't give you a healthy training ethic and teach you to fear consequences the way you should.
2. No amount of simulation prepares you for the real thing.
3. The best way to learn to fly is with an experienced pilot helping you, not using a simulator.

Looking at these arguments I would put these counter points:

1. Seeing a virtual crash as an undesirable result is really down to the mental attitude of the person using the simulator.
2. Nothing prepares you for the adrenaline shot the first time you put your plane in the air. Your heart will race, you will be all thumbs on the controls etc. However, if you have spent the time on the simulator at least you wont have to concsiously think about how to make the plane climb, for example. Your left thumb will automatically pull back on the stick.
3. I've choosen not to have an experienced instructor help me.

In addition the simulator gives you many advantages:

1. You can teach your hands/brain the correct muscle memory for your controls (If you use similar control layout - see below).
2. You can practice flying in adverse conditions. My hours flying the vortex extreme in high winds (for that plane) in the simulator doubtless contributed to my meagre success at the field today (when the wind was beyond what was ideal for the Electrafun).
3. You can practice landings. You can practice landings. You can practice landings.
4. It gives you an outlet for those days when you can't/shouldn't fly because of the weather that is much cheaper and safer than the real thing.
5. You can fly 20 or 30 simulated flights in a couple of hours. More if you are just doing a take off/land practice. Those sorts of hours of experience can't be easily gathered at the field.

I would absolutely recommend using the simulator to anyone. No it doesn't one hundred percent match the real experience but you will learn a lot from using it.

There is one final, quite important point. To get the best value from the simulator you need to use a control layout that approximates your actual radio set. I used keyboard at first, and then took my first flight. The result, I made quite a few mistakes about which controls I should be using, because I was used to tapping keys.

After that I read some articles about FMS describing how to rig your radio up to it, so you can use your actual radio set to drive the plane in FMS. That was interesting, but looked way more complicated than I was bothered with. However, there was one other great suggestion I read: Buy yourself a playstation style controller for your PC (one that has two "sticks" that you can use with your thumb). Once you have the correct stick configured for the correct control in FMS you now have a tool which is helping your brain learn that to turn right, the right thumb moves right. To put the nose down, push up with the left thumb etc. Throttle - push up with right thumb to open etc.

This is one of the most important things your simulator will teach you. It will train your mind so that you don't hesitate when trying to control the plane because you can't remember whether you pull back on the left or right stick to climb. It will also mean that after that moment of hesitation, you don't get it wrong (and close the throttle leading to a stall, instead of climbing).

Use the simulator - they make sense.

FMS will also give you an opportunity to try and fly a whole lot of other planes. Perhaps just go with the model that matches your plane for a while.

Learning to fly

So, some time quite recently I decided to get into flying model remote control aircraft. I've always been interested, but a number of factors had conspired to make me think that now was the time:

• I have come to appreciate that work is not a hobby.
  
• All of the RTF (Ready To Fly) Kits, as well as cheapness (relative to income) and somewhat indestructibility of learner planes made it seem easier to get into. I'll be honest, I'm not a patient or particularly skilled person when it comes to working with my hands so building from a balsa kit only to watch it disintegrate on the first stuffed landing would be too much.
  
• The rise of the electric powered "park flyers" means you can just head down to the local oval and have a fly, rather than driving miles out of town.
  
• A man needs to have toys. RC Planes are kind of geeky toys - but that does make sense for me.

So, to this end I started looking at model rc planes.

Although I took a look at a lot of planes available on Ebay I eventually decided to visit the local hobby shop that was recommended by a work mate. They recommended a trainer called the "Electrafun XP". So, that is what I bought, a few days later (the salesman told me to wait a week for a price drop - what a nice thing to do, and the $20 came in handy by some replacement parts, but more on that later).

So, I've had some flights, I've had some succesful landings, and some not so successful ones. I'll write some stuff up soon with some more details, photos etc.