Re: Solid Wood F1D Motorstick

From: <joshuawfinn_at_gmail.com>
Date: 09 Jul 2015 11:44:47 -0700

Evan,
  
  About 3 years ago I tried a solid stick...still have it around somewhere. It worked ok, gave proper wing wash, etc. No bracing wire was used. The deflection under load paired will with the fixed pitch prop used in testing. Never tried it with a VP.
  
  Right after that, my wife built a solid stick wrapped with nylon thread for torsional rigidity. Again, no bracing. It also worked well. What did not work as well was the solid tailboom, which brought about several observations: tailbooms are absolutely critical in terms of specifications. They must be not only stiff, but torsionally rigid. This is where the whole concept pretty much died--if you need a rolled boom, the rolled motorstick just isn't much more work. The other observation was that under the old rules, an all-solid model with absolutely no boron or carbon could be made to fly reasonably well (about 15 minutes in Cat I, at a time when I was doing about 20 with my own best models). For a junior, that wouldn't be half bad. I think under the new rules you'd see 12-13 minutes from such a model in Cat I, and probably never over 20 in Cat IV. Again, not bad for a beginner, and they could use it as a direct stepping stone from SO. It does, however, delay the inevitable of needing solid components to achieve maximum performance.
  
  What would be the biggest help would be to find a way to eliminate boron on tailbooms. I've managed to eliminate it everywhere else while steadily improving the performance of my models, but the boom remains the critical factor. Increasing the wood thickness just won't achieve the necessary stiffness, a theory proven out by my Hope's latest model--it flies great, but there is a definite performance penalty. I really do not like using boron on booms--in our humid conditions, it is a never ending battle keeping it attached.
  
 -Joshua Finn
  
 
 
Received on Thu Jul 09 2015 - 11:44:47 CEST