Re: (ATM) Cheap Clock Drive

["LUETHEN.HARTWIG" <FB4A042@phylu.physnet2.uni-hamburg.de>]

rglwp@attme.cnet.att.com (L W Phillips) recently wrote:

> Some months ago there was a discussion here about using the dial on a kitchen
> timer to drive a scope's polar axis. Another idea occurs to me: directly
> drive the polar axis using one of those timers used to turn lights on and
> off at preset times. The model I have has a synchronous motor and is geared to
> rotate the dial once in 24 hours. The dial pulls off, so the shaft could then
> be connected to the polar axis.
> 
> A rough test indicates that at least 30 oz-in of torque is available
> from the shaft of the one I have.

I think the torque won't be the limit, but the drive will be 
not smooth enough for any scope. But perhaps itr will work to drive a 
camera with a small focal length. There was something like this 
commercially available, the Purus astromount. Its performance however 
was not very impressive. It was  very depending on proper 
counterbalancing, and was only useful for short exposure with a 
standard 50mm lens ony. 



Hartwig