Re: ATM autocollimator

["Jim Fly" <jfly@hiwaay.net>]

> Suiter makes no mention of either a "cheshire" or the
> auto-colllimator, but he does refer to the peep-sight, which I was going
> to make from a film can.  What, exactly, is a "cheshire"?  

I can only speculate that Suiter doesn't mention these tools either because
the book is about "diffraction ring" patterns, mirror figuring and final
collimation via star testing and/or as such, he is not a proponent of the
use of these tools.  You'll have to ask him.

If you can get your hands on S&T issue May 1968, check page 319 for
diagrams and dicussion of both the "original" cheshire (named for its
inventor F.J. Cheshire) and the "autocollimator".  There is also an
"autocollimater" article in Issue #18 of Telescope Making , pa. 22.  The
commercial units available today (Tectron, Astrosystyems, etc.) utilize
these geometries with little variation.  Astrosystem combines their
cheshire with the "crosshair" sight tube.  The CATSEYE(tm) "cheshire"
eyepiece uses the same primary-spot centering principal, but differs in the
way light is directed to the eyepiece reflective surface.  As an effective
and "easy-to-see" "nighttime" collimation utility, the system also requires
a "reflective" primary spot.

Jim Fly
CATSEYE(tm) COLLIMATION
jfly@hiwaay.net