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Stories By Barry Slater
My Storie

Oil to sparks
After going through the oily routine of fueling up, priming, connecting the life support cable and spinning up the starter motor, I carefully carried the buzzing Ripmax Gambler over to the flight line, and set it down onto the grass runway. Hoping the little OS40LA motor would not stall, I prepared myself for takeoff.
Sitting just ahead was a interesting looking plane, about to gun the motor. From memory it was something like a Limbo Dancer, or a Panic. I cast an eye over the brightly coloured plane, and in a way that is difficult to describe, it looked purposeful. Whilst admiring this machine, it was then that I noticed that his motor had stopped. I held back, waiting for him to step out and collect it from the runway so I could proceed. But he did not. Instead the prop whisked itself up into a frenzy and dragged the plane upward into the blue yonder.
I was impressed to say the least. Obviously electric - but what a performance.

My first RC plane, about 9 years ago, was an electric glider. It clawed it’s way up, puffing away on a brushed 540 motor and 6 Nicad cells. Sometimes only level flight was possible from a hand throw, and that kind of fun does not last very long. Hence, I’ve been flying glow motor planes ever since, but clearly, as this plane demonstrated, significant developments have been made in the electric flight arena whilst I wasn’t looking.
I don’t remember my own flights that day, but as I wiped away the oil and grime using my scented baby wipes, I pictured this guy just landing, slotting it into the car, and going home to the hanger; pristine and ready for the next time. Looking back, it was then that something sort of clicked.
It was clearly possible to fly sizeable airplanes on electric power. The attractions were thus. The motor would start first time every time, it would not stall in flight, the model would come down clean, it did not need all the glow motor paraphernalia to start, and it had the added benefit of being quiet. Being an Acoustics Engineer living in a noise sensitive World, this feature was particularly appealing. In fact I remembered that there are no timing restrictions for electric planes at our site. Great!

Dawn of a new project
So, I set myself a brief, did my research, trawled the internet, set up big Excel spreadsheets, and started buying Quiet and Electric Flight magazine, a dedicated electric (and gliding) flying magazine. What I wanted was to build a plane from a kit (that narrows things down a bit!), a plane that was very slow and basic so that I could learn the characteristics of the brushless electric flight system without trying to master another plane as well, and finally something that had a bit of charm.
To cut a long story short, I narrowed it down to either the Junior 60, a vintage dihedral high wing plane with rudder and elevator, or the Piper Cub. The Junior 60 won out, and the build commenced. It took about 8 weeks to complete, and being tight I decided to try it out with parts I had around me - an old buggy motor of fairly hot wind (16 triple I think), hooked up to a 3:1 gearbox with power from 8 SubC Sanyo Nicads of 1600mAh capacity that I had bought many years ago in an attempt to boost the performance of the afore mentioned electric glider. I flew the 60 that same day, and in essence it was nearly a total disaster. I did get the plane home in one piece, but the flights (or controlled crashes) clearly needed working on. In short I needed more power and more rudder area.
For legal reasons (!) and to be fair to Ben Buckle kits, this plane was originally designed for free-flight, then later it was used with a small diesel engine to putter around the sky on calm evenings. I, on the other hand, was flying it in a stiff breeze, off fairly long grass, and with insufficient power, all of which was entirely my own fault. I also found out that there was an electric version available which would have made life easier than converting the diesel kit!

Back to the drawing board
So, the plane was grounded, and much time passed with other jobs around the house being carried out instead. I gemmed up some more on brushless technology, Lipos, and the like, and before long it was time to open the wallet! I had heard good things about John Emms at Puffin Models so gave him a call. He recommended a Mega 20/30/3E brushless motor, coupled with a Jeti 40 advanced brushless controller and a maximum of 12x6 prop. As long as my existing 8 cell SubC Nicad pack was in good order it would be sufficient.
Parts duly ordered, I then set about enlarging the rudder area. I did this by fixing a piece of card to the fin and drawing around it. I then removed the card and sketched a rudder with about twice the area (mainly stretching rearward, but also vertically to try to keep the thing looking proportioned). I was also keen to keep it lightweight, being at the tail end of the plane. The originally rudder was a solid sheet, so I cut most of it away, keeping a hinged vertical strip into which I tenoned in some horizontal rearward pointing strips in the same style as the fin, keeping the whole thing looking homogenous. I figured that replacing a solid small rudder with a built up larger rudder would negate most of the weight gain. This process turned out to be quite tricky as it all had to be grafted onto the rest of airplane, rather than making parts on a flat plan.

Back to the patch
With all shiny new parts duly installed, it was off to the patch again. This time, however, things were different. Oh, there was still a stiff breeze, which grabbed the right wing on take off and cartwheeled the little plane off to the left on the first attempt, but I was determined. I picked her up, went back to the start, and waited for a lull in the wind. I waited and waited and waited, then suddenly there was a drop. Right, here we go. It was obvious there was plenty of power this time round, and I had also noticed that a bit of right rudder was needed to keep her straight; a resultant combination of gunning the motor, more wash from the much larger prop, and double the rudder area for the wash to twist into. I made a mental note to add some right side thrust to the initially straight ahead installation.
Due to the strong headwind, and full throttle antics, she was airborne in less than 5 meters. With no elevator input on my part, she was climbing strongly at about 30 degrees. I backed off the throttle – and the nose gently dropped. Catching this slightly on the elevator and adding some power back in again allowed me to steady the ship for the first turn. This was uneventful and felt just right. Doubling the rudder area had given me the perfect amount of authority, and with 50% expo dialed in I was turning comfortably this time round. The next few circuits were a bit up and down to be honest, as applying even small amounts of power would make her pitch up noticeably, and backing off would drop the nose again. I made another mental note to add some downthrust, along with the right side thrust already noted. I also thought about moving the C of G forward a bit because the glide was neutral / a little nose up-ish.
It was soon time for a landing, and she came in fairly well, but despite full elevator for the flair out, it basically didn’t happen. I made another note to double the area of the elevator as well, to match the larger rudder. I could already sense the hostilities should any traditionalist one get a good look at the deviations I was planning. Oh well!

Home again
Going through my mental notes, the motor was raised slightly and downthrust added, together with some right side thrust. I don’t have an accurate figure but it can’t have been more than a few degrees for each axis. I then set about enlarging the elevator. In the kit this is a solid piece of balsa, so I cut a lot of it away, leaving a long strip still glued to the mylar hinges. Into this strip I cut some mortice slots, and tenoned horizontal balsa strips rearward, finishing off with a trailing edge piece to complete the built up elevators. All of this build work was done on the plane, using a flat surface underneath to keep the structure flat. With these modified feathers I found that I had added hardly any weight to the tail end, which I was pleased about. She was ready for another outing, so it was off to the strip.

Third time lucky
This time I had a bit of an audience. It was a still warm evening, and I was not alone in thinking I could sneak in a week-night flying slot. Slightly nervous due to the bumpy flights I’d had so far, I placed her on the strip and prepared myself for the flight. This time I new there was plenty of power. I also knew I had enough authority, and that the thrust lines were more favourable. So I opted for a more graceful takeoff, slowly sliding the throttle forward to about ¾, and waiting for the speed to build. A few moments passed, with very little rudder correction required this time, until she nosed up into the air. Much more satisfactory!
After a few settling circuits, playing with the trims incessantly to find the optimum setting, I set up a low and slow pass down the strip, right past my eye line. There is something wonderful about that moment when a collection of wood and electronics, assembled together into a certain order, magically defies gravity and hangs in the air, just there. With the transparent film covering it was possible to see all the structure, the electronic bits, and through the generous side windows I could make out the pilot. Ok, so he was marginally the wrong scale, and probably wondering why he was in a vintage plane rather than a jet, but still, I’m sure he was just glad to be flying - as was I.
The enlarged rudder and elevator were giving me perfect control, and at about ½ to ¾ throttle she held a fairly constant height. This plane turns beautifully, and since everything happens quite slowly, it quickly settles into a relaxing and restful experience. I heard a few complimentary murmurs from those behind me in the pits, and as I found out later, almost everyone gathered there had a Junior 60 tucked away somewhere. Had I started a local renaissance?
Barely 5 minutes had passed and it was time to land. Not because of the battery, but because it was getting late. My intention had been to get some air under the wheels, and prove to myself that it was almost sorted.

Out again !
There never seemed to be a decent weather window, so, being the impatient type I eventually went out into another stiff breeze and slightly overcast sky. The upwind leg was slow but sure, followed by a whisked away downwind leg – but the plane really needed a calm warm evening to get it into a nice slow groove. Idly running this thought through my mind I turned downwind and opening the throttle. The response was somewhat muted - had the battery gone already? It had only been 3, 4 or come to think of it probably 10 minutes of battling the wind. Yes, I probably had run it just one lap too far, and was now tasked with bringing it down at the end of the strip, into the strong wind with a definite ‘I’m landing now!’ glide angle. With a slightly early flair, and a hop skip and jump, she was down.


Finally
Well, I’ve learnt a lot about electric flight since this conversion a few years ago, with several successful own design planes to my name. Who knows, I may write a bit about the development of these too.