The first one

This is my experience with this T tail 2 meter span balsa/ply ARF electric glider kit from TopRC.

I flew it for probably 3 or 4 months before the wing joint failed in flight and it fell onto the golf course. I didn’t want to repair it so I gave it away as a fixer-upper or for parts.

So I could get it in the car I glued only one wing of the joiner and assembled the wings at the field. I added a small alloy plate to join the trailing edge. This all worked but was not as strong as it should have been and I’m sure contributed to the failure.

What I think happened: I was flying in quite windy conditions, turned down wind, air-speed went to zero, it stalled nose down, dived and the wind blew the wings off. Quite some distance below, the ground finished the job.

I have some nice keycam video recorded from the glider, including its last flight.

Flying

I was very impressed with it once I got it sorted out. So impressed that I am still considering getting another for the summer. If I didn’t have to register on line, I would already have it. The first one was on Trademe.

I had problems with the elevator push-rod sticking and not moving smoothly due to the sharp bend at the back end. It moved but jumped which caused elevator overshoot and made it very difficult to fly.

A digital servo, oil and working it eventually freed it enough.

It flew very well. It floats well and seemed fast to me. I think it flies better than an Easy Glider but is not as forgiving. Weight was about 1Kg with 2200mAh 3-cell Lipo and 1050 KV Dynam motor. Too much speed, as in a dive, and the ailerons would vibrate violently. So I soon learned not to do that.

The balsa/ply construction is delicate. It won’t take hard landings without sustaining damage. I put fiber-tape on the bottom for protection when landing but otherwise it was as supplied. I did build a secure foam battery tray under the canopy which probably helped strengthen it a bit.

About halfway through it’s life I fitted a stability controller which maintained level flight without my input; all I had to do was choose a direction. This enabled it to make use of lift that I couldn’t find. I could glide up and down the field and it would just rise.

The Build

The build took about 2 evenings. The “T” tail is a bit tricky to assemble due to the elevator push-rod. Everything else was reasonably simple. The kit was complete just needing prop, motor, esc, battery radio and four 9g servos. I used ESky digital servos because they are slightly smaller than the standard 9g types and better fitted into the wings.

Only 2 things to do differently next time:

1. I’d modify the elevator push-rod installation to ease the curve at the bottom and lubricate well before installing.
2. Permanently epoxy the wing joiner for greater strength; making a one-piece wing.

The second one

I ordered another one from TopRC for the coming summer (which didn’t really happen). I still have the parts to fit it out from the first one. All I have to do is install a new motor shaft as the golf course bent the first one.

Make sure you get the elevator movement very smooth before flying. The elevator should come to rest in the same position from up or down movement. It it’s stiff or sticking, even slightly, you could have a very exciting and possibly short flight. From first hand experience, it will be very difficult to hold level flight.

Update – March 2012

I have assembled the new one and flown it a few times now.

Under the canopy I made a EPP foam battery holder to secure the 2200 3-cell LiPo and hold the 2-oz fishing weight. The motor is a Dynam 1050Kv with a HobbyKing 10×6 folding prop.

Non-standard modifications: I made the horizontal tail surface removable for transport. Also fitted a small rate gyro to the ailerons with on/off control on channel 5; but haven’t used it yet. Our summer has been crap and it’s almost over.

Although it seems to be straight and balanced it wanted to turn left and I had to hold some right aileron in to keep it straight; more than you should have to trim out. A couple of coins taped to the right wing tip provided a quick fix a the field. I’ll probably just permanently install a little weight to replace the coins.

I’m using a Turnigy 9X radio with ER9X firmware upgrade and Corona DSSS 2.4G RF module. The servos are all low-cost miniature ESky digitals. The radio setup for this model is not complex. The elevator-throttle mix puts a bit of down elevator with the throttle to keep the nose from pitching up, which is quite strong. I have dual rates and expo make it easier to fly smoothly.

aileron – 35% expo 50%/100% DR
elevator – 50% expo 45%/75% DR – mixed with 5% throttle
throttle – 0% expo 100%/100% DR
rudder – 20% expo 55%/70% DR – mixed with 50% aileron

Initial setup is with all surfaces set to zero offset with zero trim and the CG at the position recommended in the instructions.

I’m still a bit nervous about flying it in breezy conditions after the wing folded on the first one. Time will tell.

The only similar planes I’ve flown recently are a couple of Easy Gliders and a Radian belonging to others. I prefer the Elegance –  but it’s all in the setup and everyone trims to their own taste.