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HELP!!--My dust filter ate my C8's rear cell threa

Started by paul.knight, 12/04/2009 01:46PM
Posted 12/04/2009 01:46PM | Edited 12/04/2009 01:46PM Opening Post
I started unscrewing my dust filter and realized it was stickier than normal. I get it off and realize that the threads for the rear cell of my C8 (about 10 years old) are stuck inside the threads of my dust filter. shocked Any suggestions of what to do?? I'm going to head to a camera shop to see if they can help me but wanted to go ahead and get your thoughts. Any help is much appreciated!!! Thanks! -Paul
Posted 12/04/2009 02:23PM | Edited 12/04/2009 02:24PM #1
Paul Knight said:

I started unscrewing my dust filter and realized it was stickier than normal. I get it off and realize that the threads for the rear cell of my C8 (about 10 years old) are stuck inside the threads of my dust filter. shocked Any suggestions of what to do?? I'm going to head to a camera shop to see if they can help me but wanted to go ahead and get your thoughts. Any help is much appreciated!!! Thanks! -Paul

Paul: Any time there is a problem with or question about an SCT, there is only one thing to do:

[COLOR="Red"][SIZE="Large"]Sound the Alarm for Uncle Rod Mollise 8O [/SIZE] [/COLOR]

Jon
Posted 12/04/2009 03:53PM #2
Hi Paul,
It is possible that the filter was screwed on when it was very warm and not is is cold and has siezed on the treads.
As Uncle Rod said, you can try cold to see if that will break it loose. IF that does not, you can try heating it with a hair drier and the see if it will come loose. Try to heat the filter rather than the visual back.
Worst case, you might try putting a little WD-40 on the outside threads. Just a little applied with a Q-Tip, so that it does not run everywhere. Then let it set a few minutes and try again. But remember that this stuff would not be good on a filter, so it would be [COLOR="Red"]last resort only[/COLOR]!

[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue grin
Amateur Imager
Posted 12/04/2009 04:45PM | Edited 12/04/2009 04:47PM #3
You are saying that the rear cell came off the scope
with the dust filter stuck on it? If so, try puting
the rear cell on a block of ice while you warm the
filter with a hair dryer. (Similar to Floyds solution.)
Then put on some leather gloves and try to screw them
apart.

Another solution is to get one (or two) strap wrenchs
and apply brute force. Here's a pair of them from
Sears / Craftsman. These have worked well for me,
and should not cause any damage. About $13 at Sears.

Camera repair places will also have clamp wrenchs that
allow more force. I've used these for other stuck parts,
but you need to find a set that closely match the
diameters of the parts involved.
http://www.micro-tools.com/store/item_detail.aspx?ItemCode=FLX-20-B

Attached Image:

m87's attachment for post 134353
Posted 12/04/2009 07:21PM #4
Hey guys, I read the post to mean the filter came off but it took the thread of the scope with it. He says they are imbeded in the threads of the filter.

Paul, was the filter threaded into the telescope side of visual back that attaches to the back of the scope? If so, there shouldn't be a problem if you abandon the filter as Rod suggests. If you want to continue to use a filter you'll need to replace both the filter and visual back. You might be able remove the imbeded threads with a needle but I'd suggest you not try. There will most likely be burrs and the filter threads will just gall and seize again. Next time you may not be able to remove the filter. If the filter was threaded directly into the scope's back you'd have to send it back to Celestron for a not-cheap-at-all repair.

Ok, Celestron guys. Does the dust filter thread on the back of the scope directly or into the visual back?

If it were me and my scope I'd say "oh, well" and abandon the use of the dust filter and move on.

Clear, sunny skies.
Tom Masterson
Coronado-Lunt-Daystar Solar Filters forum Moderator
Posted 12/05/2009 05:29AM | Edited 12/05/2009 05:31AM #5
Thank you all for your comments! I have attached some pictures just to clarify exactly what happened. The dust filter is a Lumicon. The threads that remain on the telescope are no the right size to screw anything else on to it. I will head over to the camera store and let you all know what transpires.

Attached Image:

paul.knight's attachment for post 134361
Posted 12/05/2009 07:34AM #6
Took it into Camera Bug here in Atlanta. The guy's going to try and get it out of there. Even if he can get it out will it be ok for me to simply screw it back on? Or should I glue/solder it back on to make sure this doesn't happen again? If I can't get this rectified could I just order the part from Celestron?
Posted 12/08/2009 06:11PM #7
The guys at Camera Bug couldn't separate the two. We have a call in with Celestron to see if they can send in the part replacement.
Instead of dealing with deadly-fogging-glue with the new part here's my plan: simply screw a new port on, then screw on a "locking ring" (like the one on my filter wheel...see pic), then screw on a 2" adapter/visual back. If things ever get this tight again the locking ring will be there so I can actually unscrew the adapter from the port. Sound like a good plan?
Thanks for all of your comments! I appreciate it!

Attached Image:

paul.knight's attachment for post 134448
Posted 12/09/2009 03:10PM #8
YIKES!!!!! I contacted Celestron Support and was told it could take up to 45 DAYS to fix!!!! cwy I hope they are kidding.
Is there another supplier for this part??? I guess I could just put the stuck filter back on, but I've exposed it to alcohol and WD-40 (I know, I shouldn't have done that) so I'm worried it could seep onto the main mirror eventually...maybe not?... :S
Oh why did this have to happen during my 4 week break from grad school when i could actually USE my telescope....