RE: F1D motor tube stiffness?

From: <joshuawfinn_at_gmail.com>
Date: 17 Feb 2014 08:48:32 -0800

Tapio,
  I've never really been happy with .013 motor tubes, particularly because of excessive twisting, and finally went up to .015, which has worked well (also allows launching on .6 in-oz or more without concern over motorstick failure (my only failures since the switch have been due to VP hubs coming apart--operator error). These sticks do not twist much, but be aware that as a consequence you may have to increase your wing offset. I use as much as 1.5" for low ceiling flying. Some fliers have gotten around this issue by setting the wing at positive incidence, and I get the impression that this would work on my models, but do not have enough experience with fixed pitch props to really say. You can also get away with some side thrust on fixed pitch props since there is less danger of tucking a blade. I'll add finally that after having seen a model equipped with carbon wing posts, I'm convinced that they are the way forward. You have to get away with less wing/stab separation, but my experience that this is only a stability issue which can be overcome without too much trouble. I have not seen a measurable performance difference from wing/stab separation experiments. I should add that my motorsticks use no boron and are only 9" long (the actual wood part). The stubs are 4" and do use boron top and bottom. Rear wingpost is mounted to the stub.
  
 -Joshua Finn
  
  
 -Joshua Finn

Received on Mon Feb 17 2014 - 08:48:32 CET