Originally posted by BBRELAND
Hello All,
I'm presently building a Dynaflite Butterfly with a 99" span wing, and my question is what could I expect if I removed the polyhedral from the wing, but left the dihedral? I see gliders with and without the polyhedral. by the way. this is rudder and elevator only plane. Would appreciate your input. I have been flying for several years so the plane being less gentle wouldn't be a problem.
Thanks,
Butch
Common error, I learned that this was wrong when I was a teenager. Cost me a model when I tried just what you're suggesting and it wouldn't turn at all and sidesliped into a barbed wire fence.
Rudder controled models rely on the coupling between the rudder yawing the model and the dihedral converting that yaw into roll. If you remove the outer polyhedral angles then the model will react more slowly to rudder inputs, not faster.
And, as I found out, since the poly is out at the tips where it has more leverage the model will loose much more of it's response than the removed dihedral would suggest at first.
Basically, don't do it. If you're trying to get faster and more powerful response out of the design then move the hinge line to make the rudder larger and use lots of throw. Up to 45 degrees.