Finding Center on a mounted bellcrank

[Ken Culbertson]

Has anybody come up with a way to measure your bellcrank centering with the plane buttoned up.  I normally mark my leadouts but this time I forgot, and my x-ray machine is in the shop for repairs. 

Ken

[John Rist]

Would a fiber optic scope work?   

[Dennis Toth]

Ken,
You can take one lead and pull full control (up or down which ever gives the short leadout), then mark the position of the end by the leadout guide. Next reverse the control and mark the leadout at the leadout guide. Now you can measure the distance and mark the middle which should get you pretty close to the neutral point.

Best,    DennisT

[Ken Culbertson]

Would a fiber optic scope work?   

I have thought of that.  Problem is that I have a 5" diamond shaped bellcrank that doesn't have a flat to use as a guide.  I do have a scope somewhere so I may give it a try anyway.  I normally do Dennis's method,  but this crank does not have equal rotation.  I made a note to myself to center it and mark the leadouts before I covered it then I forgot where I put the note! 

Thanks guys - ken

[Dave Rigotti]

Level the flap horn. You did do that before you buttoned up right?

[Ken Culbertson]

Level the flap horn. You did do that before you buttoned up right?

Yes but I am using Mark Wood's flap "box" which separates the flap adjustment from the bellcrank.  Complicated  but it works and gives you flap adjustments on both flaps that do not affect the elevator.  What prompted this was the need to replace the flap pushrod.  It was too short and didn't screw deep enough into the bellcrank ball link.  I can do that without seeing the bellcrank.  Getting it centered again after I finished is proving to be a bit more fun that I had planned.

Ken

[Motorman]

Can you get to the planking over the bellcrank? Push in two Tee pins along the longitudinal axis and equidistant from the pivot. Now your bellcrank stops are even both ways.

[Ken Culbertson]

Can you get to the planking over the bellcrank? Push in two Tee pins along the longitudinal axis and equidistant from the pivot. Now your bellcrank stops are even both ways.

That is an excellent idea but my top and bottom "blocks" are already glued on.  It is possible that I could go through the planking next to the fuselage side.  I think the bellcrank extends past the side at it's limits.  It is a 5".
Thanks!  I will let you know if it works.

Ken