Re: ATM Alt Balance and Eyepieces

[Gary Seronik <gseronik@skypub.com>]

Hi Doug:

At 02:39 PM 10/28/00 -0700, Doug Tanaka wrote:
>
>I am wondering what other folks do to keep the optical tube on a
well-balanced Dob from rising up when removing a large eyepiece - like a
Nagler - to put in another eyepiece? 

You didn't mention the size of your scope, but this is a common problem for
smaller Dobs.  There are three things you can do that are pretty simple:

1.  Balance your scope for a medium-weight eyepiece.  If you're lucky, this
means your scope won't nose dive with a heavy eyepiece, nor will it drift
up with a lightweight one.

Often though, this alone isn't enough and you have to try to find some way
to increase the resistance of the side bearings.

2.  Move the Teflon pads on the side bearings further apart.
3.  Use Teflon Sheet (as described in the October '99 issue of
Sky&Telescope) which has greater friction that ordinary Teflon, yet also
has less stiction.  I found this cured the problem on my small Dob.
4.  Use a spring to increase the "virtual weight" of the scope.  This is
what Orion does on their Dobs and it really does work.

Good luck!

Regards,

Gary

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