Celestron Optics

purchased a older C11 that's in need of some dire help with the optics, all celestron says is to send it in for an estimate but I'm thinking of just sending the primary to HL Clausing to get it recoated. does anyone have experience with having their OTA disassembled that far and how difficult was it to reassemble, (primarily getting the primary back onto the support tube that runs through the middle)

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Hi Bruce,

Getting the mirror off will I think be harder. The RTV used typically runs up into the bore in the mirror and around the baffle tube. I have no idea what would fit in there to cut through that other than a custom tool (cylinder with sharpened edge that just fits around the baffle tube and smaller than the mirror hole).

To reattach if you can do that part you'd just need some centering shims and spacers to keep the mirror centered on the tube and squared on while the new adhesive cures.

Don't forget the secondary though. sometimes it is possible to leave it attached to the aluminum backing plate and recoat without separating.

I used to jsut suggest people ship to Celestron, but with the way UPS and others have been handling packages these days, it might be lower risk to try what you want to do. Best of luck!

Dave

I think I'd let Celestron handle it....
Getting that apart and togther again probably
takes some experience....

Bruce....In re-reading your post I think you are only asking how to take it all apart...not trying to separate the primary from it's metal tri-shaped support. To do this isn't hard but I believe to have it re-coated the coating companies want only a bare mirror....and in that case the replies to your posts are correct...you would have to somehow cut away the epoxy from the backside of the mirror to release it from the metal support structure. Let me know if you still want to only take it mechanically apart as I have done it before. Gerry

Hi Bruce,

Any updates on your experience of the recoating and reassembly (recentering) of the primary (and secondary) ? I am planning of doing the same soon. Thanks.

Steven