Would Like To Upgrade Focuser For This Shorty

[refractordude]

Hello There


What two inch focuser will go with this ST80? Thanks all

[Leo.G]

https://www.cloudynights.com/topic/705565-orion-ct80-focuser-question/


Please delete if CN link not permitted Mods?



Focuser compatibility chart:


https://agenaastro.com/articles/gso-crayford-focusers-with-telescopes-compatibility.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.

[refractordude]

cool and thanks Leo

[Leo.G]

Oh, sorry, I'm sure I saw CT80 on the image, the ST80 there are options it appears.
OK, therein lies my confusion, I missed your mention of ST80 and saw the "CT80" in the image, my apologies!

The ST80 the GSO86 fits according to the chart.

[refractordude]

I made a mistake. Yes it is a CT80 and there are no focuser upgrades for it.

[Leo.G]

It's as simple as a ring (collar) that fits around the outside of the tube and a different focuser fits directly over that. My design was more a cone type unit, I'll see if I can get a photo later.
There's focusers available with the standard 3 screw holes in the collar, it shouldn't be a big job.