Hi all, I have an APM140 f/7 doublet that I obtained recently, and it has the big 3.7" focuser. The 3.7" focuser is great, but as I'm a visual observer, it's likely way overkill, even with binoviewers. I'm debating selling the 3.7, as I have an APM 2.5" focuser on hand, which should reduce the overall weight, albeit at the cost of making the scope a bit more front heavy.
With the 2.5" focuser I have, which comes with the tube mounting hardware (I believe it is the same between 130, 140, and 152?) and M95 threaded adapter; I notice the 2.5" focuser is notably shorter than the 3.7". With the 3.7" I have no problems reaching focus for visual and binoviewing. With the 2.5", I will definitely need some kind of extensions. What are you all using to get enough back focus? Are there any M68 drawtube extensions, or are most using eyepiece extensions with 2" barrels?