The attached is the assembly file I made a long time ago. I was just fiddling and it happened to behave as I wanted.
I tried making duplicates but the rotary motors I made wont spin the servo;s horn ( white circle on top) in the same way as the original in the attached assembly. The motors i make spin the entire servo motor and the horn. There seems to be some kind of conflict in the planes or axis. Can someone assist me as to what I should do to make the horn rotate alone and not the entire motor please ?