Hi all,
Today I installed a motorised focuser on my Newtonian. There was only one problem with it, the motor speed controller I was using does not supply enough current to the motor at low speeds so I am in the process of making a new circuit which should be much better. It works off 12v and draws next to nothing while in motion. I had a chance to try it out tonight and initial experiments show this will work very well. Hardly a sound from it too.
Anyway you can see by the picture below it is basically a Worm and Worm wheel set (out of a video recorder ejection assembly) with an adapter which was kindly turned up by the lathe operator at work. Attached directly to the focus knob and the assembly is bolted by one bolt to the telescope tube.
http://www.theastroweb.com/astronomy...motorfocus.jpg