Okay, let me say up front that I realize the best way to do this is buy a Nelson bellcrank and drill it appropriately. But I have the stuff pictured below handy, and I would like to "do-it-myself", so to speak.

This is for a rudder connection on a Goldberg Ultimate. What you see is the kit-supplied tiller bar that attaches to the rudder, a DuBro heavy-duty servo arm, and some small bearings, washers, and a spacer from a helicopter mixing base assembly.

I understand how to do this on a helicopter; but I have found that the solid pushrods used in that application behave differently than flexible cable in a fixed-wing installation, in terms of binding and slack.

My question is this: given that none of the holes in both parts (servo arm and tiller bar) allow for a perfect parallelogram, should I hook it up so that the distance from center on the servo arm is GREATER or LESS than that on the tiller bar?

Steve