After going down the road of using primary mirror focusing on my C11, I came to the conclusion that was not the way to go. Focus was unrepeatable with unacceptable amounts of backlash. I ordered one of the Optec FastFocus SMFS units and got it installed, but had an anticipated problem. When leaving the scope set up, there's no way to cover the scope's corrector plate when not in use. Yeah, a scope cover does it somewhat, but especially this time of year in the southeast, pollen gets everywhere, even under a scope cover.
I ordered a new dust cap from Celestron at https://www.celestro...-cap-for-cpc-11. Also ordered a Tovolo 1-Quart tub from Amazon at https://www.amazon.c...arden,70&sr=1-4
I wanted the cover for the focuser itself to be rigid, as it would protrude from the front of the scope, and needed some surface area on the rim of the tub to bond it to the dust cap.
For the dust cap, I marked the center of the dust cap, drilled a pilot hole. Then using a 4" (102mm) hole saw, cut a hole in the center of the dust cap. After cleaning up the loose plastic filings with a round **** file, I used epoxy to bond the tub over the hole I made.
The result looks like it will protect the corrector plate from accumulating dust and pollen and protect the SMFS as well.
I'll still have to demount the SMFS for transport and storage in my Celestron case, but while set up, this provides a little extra protection.
Thoughts?
-- Gil
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Edited by astrocycle, 09 April 2022 - 06:33 PM.
