THE SCRAPSTER
(Model No. 39)

This home-made was a copy of the Balsa USA's Scrapper. My model was built after seeing an advertisement in an American modelling magazine (actual picture below)

The unusual looks were an immediate attraction, I just had to have one. The advertisement said that the model is 'definitely not for the faint of heart, the slow of thumb, or the dim of wit,' and that it 'will keep you on your toes when you open up the throttle' . . . . irresistible!

But importing a kit would take "too long" and would probably cost too much, so measurements were assessed, and scaled up, from the picture. My version differs from the Balsa USA kit in that a rudder has been incorporated. Scrapster also sports a tail-dragging undercarriage (whereas Scrapper is hand-launched) as I prefer take-offs and landings to hand-launches and belly-flops

The first flight was made somewhat exciting by extreme twitchiness and also by "digging-in" during turns. For the second flight the rates were reduced and both ailerons were raised slightly, producing a very nice-to-fly model

On the third flight aileron flutter resulted in one of the ailerons becoming completely detached from the wing. The wing-mounted aileron servo was dragged right out of the wing, complete with its mounting blocks and the two half ribs they were glued to. The aileron itself was left trailing in the slipstream, connected to the model only by the servo cable, which made the subsequent landing quite a nerve-racking affair

But much to my surprise, the actual touch-down was surprisingly gentle. On reflection the flight characteristics had hardly changed due to the loss of the aileron (and despite the large hole in the covering of the under-side of the wing) so I went ahead and flew a fourth uneventful, but careful, flight before packing-in for the day

The aileron flutter: The aileron flutter happened during a fast, high-G turn, and the gears in the Hitec 101 aileron servo were completely stripped. Somewhere along the way the aileron became detached from the wing and this in turn dragged the servo out of the wing - the mount itself letting go. I find it amazing that the wooden servo mount actually broke, rather than the tiny plastic pin which is part of the quick link I had used on the aileron push-rod

After several "false diagnoses" I finally realised that the false trailing edge of the wing was causing the flutter by flexing under stress - this was finally cured by stiffening it up a little with CA! Well, you live, you learn

This is the only model I've ever had which would fly "hands-off" either inverted or the right way up - yet was still very agile, aerobatic, and a delight to fly
 

Sold to make room for next project  25.09.03

 

Tony's Model Planes