Brittain Auto Pilot System

[ahe]

I have a Brittain Flight Control System (Positive control) on my M20A. It is this system

http://www.brittainautopilots.com/web%20site%20art/Product%20Photos/B2D.jpg

From this page

http://www.brittainautopilots.com/Back.htm

The system works but the little control wheel in the bottom does not seem to have any effect - what should this wheel do?, and what does the button in the right?

My M20A manuel does not notice anything about the function of the auto pilot system.

Best regards

[N601RX]

I think it is the trim wheel for the roll axis.  For the STC to be legal your POH should have the amended pages that tell how to operate it.  Brittain is still in business and is a good company.  If you call or e-mail them they will be happy to send you the operators manual for it.