[AG Hybrid (Adrian)]

Originally Posted by Don Pensack

The black ring that threads onto the top of the focuser, into which the 2" and 1.25" adapters fit, has a 1-15/16" inside diameter that prevents long 2" accessories, like barlows or coma correctors, from passing through until their shoulders rest on the top of the 2" adapter.
If the ring on the top of the focuser is machined out to 2" (and there is enough material to do so) inside diameter, then 2" accessories like the HRCC will insert much further and require much less in-travel of the focuser.
It can be done with sandpaper while you're sitting watching TV. It doesn't take much.
When the 2" accessory like the HRCC passes through the ring on the focuser, you have removed enough material.
This modification, by the way, will have no effect on the fitting of the 2" or 1.25" adapters in the ring on the focuser.

I'll take a closer look at this tonight when I get home from work. If I'm honest though. I don't think any solution will involve me with sand paper grinding away at a metal pipe while in the living room in front of the television.