Clutch Problem

solissydney (Ken) · #1 18-12-2009, 12:36 PM

I am no longer able to lock the Dec clutch on my My Celestron Ultime 2000.
I took it apart but have been unable to fix the problem completely. Can't make it lock fully.
Has anyone been through that particular exercise and be of assistance?
See images.

casstony · #2 18-12-2009, 02:09 PM

On other similar scopes I've had the clutch could be made less slippery by removing grease from the clutch plate faces. I've never seen an ultima 2000, but I'm guessing the clutch plates are inside the second black circular housing behind the part you've disassembled.

I think the pieces you've pulled apart are simply for applying pressure between the drive plate and clutch plate.

solissydney (Ken) · #3 18-12-2009, 03:02 PM

Thank you. Tried that, made little or no difference.

solissydney (Ken) · #4 18-12-2009, 03:53 PM

Inside the housing is a brass bush in which the shaft reside.
There is just a washer behind that bush. Nothing else.
One would assume some wear most have taken place some where, but where?
The best result I had was with the first washer, the leftmost in the image, attached.
Adding any of the others washers, seen in the image, including the roller bearing 'washer', made it less efficient. It really has me baffled.

solissydney (Ken) · #5 18-12-2009, 04:21 PM

Tony.
great news. I had a third look behind the bush and saw what looked liked large disks.
Removed the tube from the forks and there were the real clutch plates that one would expect to see. Just like the RA clutch that I fixed some years ago, simply by inserting a washer at the back. The newly found Dec clutch plate are very oily, so will need a good clean.
Thanks a lot Tony, without you, it would have taking me a hell of a lot longer to work out the problem. I will take an image of the setup and post it.

Ken

solissydney (Ken) · #6 18-12-2009, 04:41 PM

See image for an very greasy clutch plate.

casstony · #7 18-12-2009, 05:36 PM

Glad I could help Ken. That's a beautiful looking scope and I like the fact that you can release the clutches and not lose alignment.

solissydney (Ken) · #8 18-12-2009, 05:48 PM

Fully clutched mounts is something I have been used to since I first got into astronomy. First an 6 inch German Eq. then the Astro mount with my, now,12 inch newt. and also the Ultima. I would dislike having anything else.
I tested the clutch after washing the oil and grease off, it works beutifully. What I have to do now before I re assemble the scope is to have the brass bush sleeved. It has quite some slack in it.
Thanks again.
Ken