Just out of curiosity, what kind of routine maintenance is there that must come from behind? I simply do NOT have the space to waste 2' from the wall. My last 12x39 lathe/mill combo sat in the exact same spot as this one will go and never had to get behind it in the 16 years I had it in place. I did have a piece of sheet metal on the wall that met with the chip tray to keep swarf and anything from falling behind it. The new lathe has a built in backsplash so I don't see that being an issue.
Our 13x36 lathe at work is also against a wall and has been since I installed it in 1988. Never been moved since.
I would be open for reasons why as in my experience I have not had to get behind these machines so if I am missing something, please explain.
For my knee mill, I wanted it either in a corner configuration, which is not possible, or in an open area to get 360 degrees around it. This I was barely able to afford to give up some space to accommodate.
Mike.