On 30 Nov 2004 01:28:24 -0500, Allan Adler
wrote:


"Kelly Jones" described very clearly and in great
detail how I could make a thorough check of the condition of the rack and
pinion on the telescope. I just have a few questions:

Allan, as so often happens in this group, most of them have gone off
the deep end again.

You do not have to do a pattern check on the rack and pinion, that is
for precision gearing, and precision gearing is not found in focusers
under the $250 range. THe pinion is probably cut from extruded pinion
wire rather than being a cut gear. The rack, if it's a gray metal as
you describe, is die cast zinc, and no degree of precision there
either. It simply is not needed. The optical comparator is massive
overkill, just looking at the teeth with a good hand lens will show
the problem if it's bad enough to cause a real problem. The racks and
pinions in my old Edmonds are now over thirty years old, were never
the epitome of quality to begin with, and don't cause any problems in
use. If I were using one of the remote focusing units, the backlash
might be a problem, but as I focus "eyeball to the eyepiece", it is
not.

Lube, I lube the drawtube, but grease and oil only attract dirt to
cling in the rack, so mine runs dry except for the shaft and the
drawtube itself.

My final advice, put it back together, take it out and use it. If
nothing else, it will give you far better views than the telescopes of
Galileo, Herschel, Newton and others. IF the drawtube moves when you
turn the knob, it's doing what it's supposed to do. A lot of time can
be taken with technicalities, without looking at practicality. And
already has, the prime question is "can I get this thing in focus",
and if the answer is yes, going deeper into it is only wasting time
and money. Your time would be better spent in a dark place, with the
scope, even just sweeping starfields to see what is there that you can
resolve with the instrument.

Have fun.