I'm a newbie here.
I'm building a semaphore signal for my live steam train club, the Los Angeles Live Steam Railroad Museaum LALSRM....(http://www.lals.org/). I'm using a motor/encoder/gearbox combination I read about here: (http://www.robotroom.com/FaulhaberGearmotor.html). I've changed the output gear to one I bought which is indexed and connects via a timing belt to another indexed gear on the semaphore rotation axis shaft. I've got a 1:3 (12-tooth to 36 tooth) gear ratio. So according to the article above the motor will make ~141 rotations per one rotation of the output shaft.