Re: [ATM] Plastic or inexpense gears

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

Gears do have the backlash problem and compounding gears together
to gain the larger ratios does have a real problem with backlash.
One way is to make your own large worm and gear by the casting of
a threaded rod method and some epoxy for real cheap and the
periodic error on those is usually good enough to use an
autoguider with.
Alternately, just spend the money on a worm and gear and be done
with it.
There are also the choices of friction drives which will work
well with a fairly well balanced scope.  These are nice in that
you can easily gain huge ratios without problems and actuallly
work better with the larger ratios than with smaller ratios.
They will slip tho with loads rather than stall out so are not
that good for non-feedback GoTo drive systems.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


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