Interesting about the "servo"...
How about I control the postion as stated in one of the comments.
I have a pair of these fellas on an educational robot platform (diy). They work great. I’m sending ‘microsecond’ commands from an Arduino – rather than angular commands – as it offers higher resolution.
1000uS is full speed forward
1500uS is STOP
2000uS is full speed reverse
…anything in between gives a proportional speed. Very handy.
Cheers