I’m nearing the end of my MP-CNC build. It’s worth reiterating what everyone else is saying: this is a fantastic project; thanks so much for sharing. I’m starting to think about the electronics
I plan to manually set the spindle origin according to the corner of the area I want milled (as it would be a pain to accurately line up stock each time). However, I’d like semi-automated and repeatable tool changes, ideally without having to manually line up again each time. I’ll be using the LCD screen so the less I have to fiddle with little buttons to jog the head around the better. After initial experimentation I plan to add end-stops and a z plate.
So I was thinking, for a tool change, I’d like to: lift the head, stop the spindle, move to a position to change the bit, then pause.
On resume: re-home the spindle, start it, then return to the last milling position to continue. This should be fairly straightforward g-code.
I am wondering however what g-code would be needed on job start in order to calculate the home position offset from the origin? G92 or M206? Can current x/y/z positions be used as inputs to these commands?
Hope I’m not over-thinking this. As steppers can be left energised during tool changes, the z offset is the only really important one I guess.