This is a common problem with Alt-Az fork mounts. As stated, one can set altitude limits. This post considers what can be done mechanically.
With my 8" OTA fully forward, I can just make it to the zenith, despite the desirable 105mm back focus of a Celestron x6.3 focal reducer with a ZWO NON-cooled camera. See image below.
With any cooled camera, there is no chance of me getting close to this, and I would then have to use a diagonal. But I use a ZWO ASI294mc at f/6.3 for most EAA and Atik Horizon (cooled) on HyperStar f/2 at other times. I found that I don't need cooling for short exposure EAA at my mild climate location hence I deliberately went for the non-cooled ZWO option for use at f/6.3 or f/10. If on a wedge, you will enjoy significantly more clearance, but I hated using my wedge. Too cumbersome and tedious.
As somebody is bound to ask;.my optical train here is OTA; > Celestron x 6.3 FR; > Celestron T-Adapter (part #93633-A); > Baader Varilock (#2956946); > ASI294mc Camera.
What can be seen below my mount are two plastic ABS Boxes screwed back to back and slid onto my central tripod rod above the leg spreader. I neatly hide excess cables and AC/DC adapters inside these. Affixed to the ABS Boxes are my Intel NUC and MKIT20 Focuser controller. Three cables run to a ring suspended under the centre of my my OTA all neatly inside the white spiral cable tidy depicted; hence camera USB3 cable; Focuser USB cable and power cable (only for Atik Horizon). I can swing the same cables forward or back depending on if I am imaging at f/2 or f/6.3.
I might add that making my OTA quite heavily front end loaded and unbalanced seems to improve my GoTos and tracking. I use the same extreme forward OTA position with HyperStar and the mount copes without any difficulty.
Edited by Noah4x4, 25 February 2021 - 09:45 AM.