[bojan]

Steve, this really looks very good :-)

I like your clutch idea...

Some time ago I posted my clutch solution in this section - I mounted the motor in eccentric barrel, so I can adjust the belt pressure/slippage (there is no teeth on focus wheel, just a groove for belt) by rotation of the motor assembly (it is coreless DC motor, with gearbox). However, engaging the clutch moves the focus, so I think your solution is somewhat more complicated, but better :-)

My focuser is independent of Bartel's system - sometimes I just do not feel like powering-up the whole thing.. It has its own controller box (with dynamic breaking and powered by internal 9V battery, it is there for 5 years already and still working :-)