Geometry and Leveling of Equatorial Mounts?

I got into a little argument today with an expert on telescopes and
just about everything to do with them (not a self-styled expert,
either, but a recognized expert). I showed him my drawings for a pier
that I'm going to have built.

My base mounts in the same manner as an AstroPier
http://www.astropier.com/installation.html, which means that it will
be mounted slightly above the concrete foundation by the use of hex
nuts on the J-bolts above and below the pier's base plate to allow for
precise leveling of the top surface to which my Milburn wedge will
mount.

The expert said that it is unnecessary to mount the pier in this
manner; it should bolt directly to the concrete footing for better
stability. He said that it does not matter whether the pier is exactly
perpendicular to the base; a couple of degrees in any direction will
not affect telescope tracking.

I argued that the base of the wedge (and, if shims are to be avoided,
the surface on which it mounts) must be as level as possible;
perpendicular to a line dropped from the bottom of the wedge to the
center of the Earth, if you will. I've always assumed that that is why
they put bubble levels on wedges.

Otherwise, I reason, as the telescope follows a fixed star, adjustments
in declination will be required as well as movement in R.A. The result
of that, I believe, would be slight field rotation over time.

So, who's right?

Davoud

http://www.davidillig.com/observatory.shtml

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usenet *at* davidillig dawt com