Mopzilla

Hi everybody! I was just reading about bipes, because I ordered a small 25" FF bipe kit to convert to r/c.

Now, let's say the engine crankshaft is right on the centerline between the wings, when looking from the side. If all the controls are set with pushrods and surfaces at right angles, then technically, perfect rolls should be acheived. Well, what if the engine is off center, like it is many times - could a linkage be changed up to accurately return the rolling to the centerline?

Bipe Flyer posted these drawings in another thread. Somebody noted the throw differences in the first drawing. This reminds me of how I use different linkage positions to get accurate Ackerman angles in r/c cars (I even set it up so that when the offroad truck banks to the side, the outer wheel turns into the turn more, and pushes harder- maybe it's not needed).

In the first drawing, when the bottom aileron goes down, the throw for the pushrod is increasing until it is 90 degrees with line created by the connection point and hinge point of the surface. Then it is decreasing, but by that time your surface is already at its max. While this throw is increasing, the throw of the top aileron is decreasing, and it's running out of room to pull with. This means that the bottom wing will push harder than the top wing. On the other side of the plane, it will be the same, except reversed- the top wing will push harder than the bottom wing. Could this linkage be modified to reflect an off-center engine?

In the second pic, the control surface/linkage connection point is in the same relative place on the surface, so throws will always be the same, and the plane might start doing a barrel roll... well, barrel roll when judging by the engine centerline.

I would like to create a system where this connection between engine crank centerline and control surface deflections is accurate, and can be accurately adjusted. It probably isn't worth it, but I want to make it perfect. Anybody done this before, or thought about it?