Re: [ATM] Crayford focuser pinion problem

["Bob May" <bobmay@nethere.com>]

The drawtube needs to be made of something that won't bend under the
pressure of the pinion.
I tend to use aluminum at least 1/4" thick for mine and a piano wire rod for
the drive pinion.  I also tend to make the bearing for the pinion all the
way across on the side away from the drawtube to help support that pinion
rather than the big slot that many tend to use.
The steel on aluminum friction is more than enough to hold almost anything
that you will want to put onto the focuser and if it does slip, a little bit
of tension adjustment on the pinion will hold the tube in place without
problems.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net


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