|Going Electric - With Electro Flyer!|
Firstly I would like to thank everyone that has shown interest in my first article. I am flattered with the response. The Electro Flyer name was not my idea, but I quite like it, so here we go with Part 2.
This month I will continue my look at electric flight, which to some may be a little unorthodox. I prefer to "Try" it based on my theory as opposed to getting all the calculators out to see if things might work.
For example, I have been very busy since last month continuing work on my latest model, a Vintage style Radio Queen. Now, if you said to most electric flyers that you wanted to fly an 82" span electric model turning a 16 x 10 prop using two 2000mah 8.4V packs and expected flight times of between 15 and 20 minutes (at least) in almost complete silence, then I think you would be looked at like you were mad. I would have done exactly the same had I not strapped the right motors to one of my Team Gear gearbox's, and ran it flat out for 17 minutes at 4 lb of thrust ... I couldn't believe it either, but that is the beauty of practical modelling.
So here it is, the Ratby Team Gear Scale Twin powered Radio Queen. A big beautiful model at 82" span. I have tried to finish it with a vintage feel. I have built it with a few modifications including a two piece wing for ease of transport. And as there is no cylinder head on an electric motor, I have been able to put the original top cowling on to give a nice smooth look to the front end.
I also added a couple of vent holes to keep the motors cool and an outlet in the bottom of the engine bay for through flow. I looked carefully to find the right model to suit my scale twin motor unit and one extra bulkhead and the engine bearers turned on end worked perfectly. It fits like a glove giving perfect clearance for the gears and easy access for wiring and lubrication.
No extra lightening of the structure was required. Traditional closed loop wires for the rudder. The tail plane looks like it's held in place with bands to keep the model authentic but it's also epoxied in place as any movement would affect the control linkages and I was not going to risk the model when it was only held with a couple of bands! A local company produced the graphics for me and I finished it off with a little pin stripe.
So there it is - but does it fly I hear you say! Yes, it most certainly does. On the afternoon of Saturday 19th May it was ready for that always nervous first flight. So off I went to my local private airfield (which has just been purchased by an R/C modeller - great!). A few packs of cells and a leisure battery in the boot and there I was - ready, charged and no excuses not to try it.
A high pressure region had moved in and it was dead calm. I would have preferred a light breeze for that extra airspeed, but if it was OK in this then it would certainly get more flight time in a breeze. There were a couple of problems, both down to my 4 channel brain not allowing me to move the "Aileron" stick during taxiing, but I did get my 3 channel brain turned on after the second attempt and off she went. On the longish grass strip she picked up speed quickly, tail up, then off she went. Some down trim to allow for the full power take off, cleanly up to about 50 feet and then throttled her back for a steady climb out and the first circuit.
Three circuits to get the feel for her, then a practice approach to prepare myself for landing. I soon realised that she would float forever, even with no wind and so a couple of more practice approaches to work things out and I was happy. I flew for about 10 minutes and although she still had power left I brought her in just in case I needed it for another circuit.
Back on the ground and with the wings off, batteries out - WOW! They were only just warm. Lets get the next set off charge. At this point I realised that I had picked up an old set of 2000's that I had cooked during early Team Gear tests. Oh well, I needed to check whether she would do the sort of flight times I had aimed for, so I knew that I could add a fair bit on when using a decent set of 2400's as compared to this set - so off she went -stopwatch on.
She is more than comfortable on ½ to ¾ throttle for circuits and will climb very quickly on full throttle. She was an absolute pleasure to fly. After 13 minutes she was starting to sound a little slower on full throttle so I brought her in - a smooth graceful decent and touchdown. Based on this I am happy that with a good set of cells she will be up there for a good 15 minutes - MISSION ACCOMPLISHED!