Correct in that I don’t use homing switches. That said, I still have 100% confidence in a repeatable X-Y homing process by use of my X-Y hard stops. I only have one coordinate zero (G56) which dimensionally relates to home position. In my case, there are 3 reasons for homing:
- By requirement of the Acorn controller (well, really the software)
- To validate the soft limits
- For reference to G56, as well as other coordinates I may want to refer back to
My G56 is typically used with one of my 3 coaster fixtures. On some occasions, I don’t even do an accurate home, I just jog the machine close to home & set it, just to make the software happy.
In the case of the above fixture, I actually zeroed on the fixture pocket itself rather than the part because it was just easier to do it that way. With the non-movable fixture in place, I can confidently reload parts and be assured good repeatability.
I most generally zero in the center of my parts. Occasionally, as in the first process of the above job, I just set zero at the lower-right corner (for no specific reason) to cut out the part profiles. This zero was re-usable in a sense because I had a visual orientation of where to stick down the 6" x 6" polycarbonate sheet onto my 6" x 6" self-stick flooring piece that was stuck down to my table as a low-profile “wasteboard”. Obviously in this scenario, it was not important or necessary to be dead-accurate in placement of the polycarbonate plates, only that the 8 parts would fit on the plate. Most times my program zero is just some arbitrary zero point set once the part is on the table, with no immediate concern of where it relates to home position.
