OK, I was writing while you guys were adding more tid-bits for great information. I'll let it go as it was written below....
Simpson 36, The wall mounting leads to some peculiar problems - In actuality, I cannot think of any reason that the machine couldn't be mounted on the wall. Eye height would be good. So, steel toed shoes and a face shield would be a must. There's a benefit! The smoke would linger longer behind the shield - more effect - better machining visualization. YEA!
Thanks Hood, that makes very good sense. Very well explained. The ability to 'zero' at some distance from actual home would require another switch but may be a real time saver at boot-up time. A Mazak CNC at Jefferson Lab does a 'backward' home for Y (I believe) and that machine refuses to run a program at all unless it has been homed. It goes positive Y to 'home', then zeros negative to actual home. The Mazak is the machine that has led to my confusion about this homing business in the first place. X homes as you would expect; negative - table moves left. Y homes with the spindle to the far side of the table or positive......Have I misinterpreted what the machine is doing or is this description correct?
Appreciate it !
WAC