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Main
Date: 17 Dec 2006 21:47:46
From: starburst
Subject: smooth c11 focus?
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Hi stargazers-
I've recently picked up a C11 Ultima (black tube), and while the views
through the scope are pleasing (to put it mildly), the focusing action
sucks. It's far too stiff for my taste and I'd like to make it smoother.
A quick google found lots of DIY performance upgrades for the Meade SCT
focusers, but nothing really on the Celestrons.
Can any of you point me to a site that might explain how I can adjust
the focuser on a C11?
And by the way, the scope also came with a CCD camera that I don't need.
Any of you folks interested in a SBIG ST-6 with a filter wheel and
terrific SBIG color imaging filters? It's a pretty bitchin' little setup
for the fellow looking to get into CCD on the cheap... 18th magnitude in
one minute on an 8" SCT...
Thanks, and clear, dark skies to one and all-
Chris
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Date: 18 Dec 2006 09:54:42
From:
Subject: Re: smooth c11 focus?
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starburst wrote:
> Hi stargazers-
>
> I've recently picked up a C11 Ultima (black tube), and while the views
> through the scope are pleasing (to put it mildly), the focusing action
> sucks. It's far too stiff for my taste and I'd like to make it smoother.
> A quick google found lots of DIY performance upgrades for the Meade SCT
> focusers, but nothing really on the Celestrons.
First, try the "move the grease around" solution. wtist the focuser in
one direction until the mirror tops/bottoms out. Then go the other
direction until it bottoms/tops out. Do this a few times and the
original grease will be distributed alng the focusing tube.
Alternately, you can at least try to fix this yourself. There are three
tiny screws (should be allen screws) holding the focusing berarings
onto the rear housing. loosen these screws and move the focuser around
in tiny increments to see if there is a place where the focuser works
better, then tighten down these screws and you are set.
Other than this, there are JMI attachments (crayford) and similar.
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Date: 18 Dec 2006 13:26:55
From: Mark D
Subject: Re: smooth c11 focus?
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Hi, The cheapest approach will be to rack your Focuser Knob from lock,
to lock about 10 times, and see if this helps. This might help
re-distribute the grease on the Primary Mirror's baffle Tube, and help
smooth things out a bit.
The Focsuer Assembly is not all that hard to remove from the back of the
Tube, and if my thinking is right, there's along Screw Rod that may
benefit from a drop of good oil. Just be careful, take your time, and
carefully note how things come apart when you do this.
The other, more costly options are a Starbright Instruments
Micro-Focuser, marketed by Starizona, or the full blown Starlight
Instruments Feathertouch Focuser which attaches to the Large Rear Port
(With thier Adapter) to the C-11.
The 2-Speed Starizona Micro Focuser will definitely help some, and of
course the Rear Mounted Feathertouch will be the smoothest focusing
Mechanism you've ever had the pleasure of putting your hands on, but of
course will add about three, or so inches to the infocus of your
Telescope. This is usually not a problem with SCT's though which have a
large range of focus.
This newsgroup isn't exactly the best place to sell your astro goodies,
and may I recommend Astromart Clasifieds to sell the SBIG Cam.
The Clasifieds are free, just make sure you provide a legitimate, real
email address, and correct personal information. The sale of the SBIG
should provide you with the funds, should you choose to purchase one of
the Focusing Units I mention above. Best of luck, and I hope this helps
you. Mark D.
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