The Ply Moth Story,

or The Evolution of a Model.
In 1997 the Ply Moth was designed and built, the idea beeing that it would be an easy to build scalish model. The wing span was 170 cms, power was an old
O.S. FS-60 openrocker four stroke.  

   The model was a nice flyer, but the vertical fin seemed too small, and was substituted for a bigger one. Ply Moth was crashed twice, at least the second crash caused by a faulty solder connection in the receiver.
The second time there was no inspiration to rebuild the model as originally designed, so a new fuselage was built.

Björn's.©2002

  This time a low wing one, using the original tail feathers, landing gear and wing. The performance was boosted by using an ASP .80 FSR engine, which provided lots more thrust than the old O.S. The new fuselage was now much more rugged and nicer to handle, but of course a little heavier. The Ply Moth Mk II was born! It flew like a dream the whole 1998 season

    In July 2000 a test bench was needed for
a Saito FT-100, so the nose of the Ply Moth was sawn off, a new fire wall glued to it, a little black paint and the new engine added, and off it was to the field again. The whole season 2001 was also flown in this configuration.
On the left son Mattis with the Ply Moth on tow.

    In spring 2002 time for a change had come. This time the idea being to build a twin engine model. Engine mounts for a couple of Saito .56:es was added to the wing. Without an engine in the nose the model no longer looked scalish at all, but now it really was only a low tech test bed. The sound of the two four strokes was very pleasing indeed, and the thrust to weight ratio was better than 1:1 ! The accelleration of this model was... brisk! A take off at full throttle required a ground roll of only a few meters.

On the right the twin engined Ply Moth is seen taking off.