https://www.cloudynights.com/topic/7...user-question/
Please delete if CN link not permitted Mods?
Focuser compatibility chart:
https://agenaastro.com/articles/gso-...atibility.html
Sorry, CT80 is down the very bottom with mention no after market focuser will fit. This is when I'd suggest you maybe contact Joshua Burns on this site, you'll find reference to his machining capabilities and helping many others.
It seems it's an unusual size tube along with 3 mounting screws into the tube to attach the focuser.
I had the same thing with an old Tasco 80mm refractor and I paid a person to machine up an adapter to fit a Williams Optics DDG Synta focuser, now obsolete but in my use an amazing piece of equipment though I've seen many negative comments. The same focuser also adapts to my 102mm refractor and my 152mm refractor.
I'm not recommending the focuser as such but more mention you can fit most focusers by way of an adapter, in my case custom designed and machined from alloy. The one downside with
MY 80mm is the focal point was too far from the primary lens to obtain enough in focus focus so I cut the tube down, something I was extremely hesitant to do.
Same cheap Tasco has a vixen lens cell and home made baffles so it's a great scope compared to what came out of the box.
Sorry, I'm certainly not recommending any of what I did to you as an option.
