[Shawn]

Originally Posted by Roger Davis

The optical axis is not always coincident with the mechanical axis.
The important thing is to optically collimate your instrument.
See:

http://www.kendrickastro.com/astro/p...ollimation.pdf

I thought this might be the case, which brings me to another question, If the optical axis in not coincident with the machanical one, how would this affect polar allignment, if indeed it does to any significant degree...