Small tail 360 with Stec50 autopilot. 

 

AP works OK to maintaining heading - but pitch enters oscillations eventually becoming so severe requires disconnection of AP after about 30 - 40 seconds.   Incredibly there is no 'gain' adjustment in the pitch axis of the STEC 50.  I have read about replacing resistor on board to modify gain - but a little uncomfortable with this option.  No slop in the linkage.

 

Have not dug into the servos yet - but hoping there is a way to mechanically reduce the 'gain' by extending the servo attachment point radially outward on bellcrank - or ??

 

Alternatively thinking about installing BMA EFIS Gen 4 system with new servo actuators.  Anyone have any experience with BMA gen 4 EFIS on a close coupled LNC2? I do know there is gain on both axis.

 

Thanks again for the help.

Wayne