1.25" low-profile focuser advice

My son is using a UO 1.25" helical focuser on his homemade 5" f/11.4 newt,
and this is a pain in general, and especially so for imaging. I am looking
to get him a better low-profile focuser which doesn't rotate the webcam.
Looks like JMI has a nice 1.25" Crayford with a short drawtube that would do
nicely. Any other options that folks would suggest? Thanks.

Dennis

The Crayford design is an excellent one as it doesn't have any backlash like
the old style R&P focusers do. Their only problem is that they may move
with gravity if you put a heavy load on them but that can be fixed by
putting the focuser horizontal rather than vertical.
FWIW, I make my own Crayfords for my scopes.

--
Why isn't there an Ozone Hole at the NORTH Pole?

FWIW, I make my own Crayfords for my scopes.

Do you have anything on the web about the construction? It has always
seemed to me that the hardest thing must be getting a good parallel flat on
the drawtube (unless one has a milling machine).

Dennis

Dennis Woos wrote:

My son is using a UO 1.25" helical focuser on his homemade 5" f/11.4 newt,
and this is a pain in general, and especially so for imaging. I am looking
to get him a better low-profile focuser which doesn't rotate the webcam.
Looks like JMI has a nice 1.25" Crayford with a short drawtube that would do
nicely. Any other options that folks would suggest? Thanks.

Dennis

I couldn't be any happier with my JMI 2" Crayford focuser. It has a set screw
you can tighten a little for heavy eyepieces, but this makes it harder to turn
the focusing knobs. The adjustment is quite small and you might still have a
problem with really heavy items. But how often is your scope pointed at the
horizon? A Newt will be pointed at a sharp enough angle to prevent the focuser
from sliding inward, most of the time. The 2-inch focuser may be a better
choice for a heavier object like a digital camera, but you need an adapter for
1 1/4 inch eyepieces.

L Brown http://www.antiquetelescopes.org
http://home.fuse.net/astronomy