another control system question

What line spacing do you use at the control handle w.r.t. the length of the bellcrank? i.e with a 4" bellcrank do you use 4" line spacing at the handle for a starting point, then adjust to get the desired sensitivity? I would expect wider spacing to increase sensitivity...

What's a good rule of thumb for a starting point for a new model?

>What line spacing do you use at the control handle w.r.t.
>the length of the bellcrank? i.e with a 4" bellcrank do you
>use 4" line spacing at the handle for a starting point, then
>adjust to get the desired sensitivity? I would expect wider
>spacing to increase sensitivity...
>
>What's a good rule of thumb for a starting point for a new
>model?

Although a bigger belcrank will allow a wider handle spacing, this one is really going to be dependent on where the pushrod is attached to the belcrank, the horn length, surface size, etc. It is still a package, and if you have "quick" controls on your plane, you will still need narrower spacing at your handle. And, of course, there is only a certain amount of movement on the belcrank, so that limits how wide the spacing can be. But, bigger belcranks will allow wider handle spacing.

I could measure Matt's, but I don't know how typical his is. And he varies his spacing (slightly) as the flying season progresses.

Start at 3.5" to maybe 4" and take it from there. Most of mine, for what it's worth wind up around 3.5 with a 4" bellcrank but sometimes with slight variance in the up or down lines to partially adjust for airplanes that seem to turn better one way than the other or perhaps some quirk in the way my hand moves.

I highly reccomend using one set of lines and a handle that once set, stays set. If you have more than one airplane, get another set of lines and another handle. The Tom Morris handles work well if you do this. The inputs seem much more precise than with an adjustable cable type handle and the adjustment is always exactly correct. I, for one, cannot fly with a handle that is even slightly off adjustment.