Automatically recording home offsets in case of power failure

The level of precision you need in the work will play a role in how you can achieve this goal. Stall homing is pretty good but does have some variability in my testing (+/-.2mm, can be more if there’s debris in the way, @Machinist posted a method using additional stops here Stops for Homing that can help with the debris buildup). If you need better accuracy you will need to have a solid point that you can probe then offset from there. Unfortunately there isn’t a way to set a home based on probing a point so you’d need to use the absolute offsets for that point and your work offset.

I use a lot of fixtures for my work, I will usually have a corner designed into the fixture I can probe, then from there I know my distances to the work offset so I’ll probe the corner then use the MDI tab to execute a G0 X50 Y50 Z50 (replace the value 50 with your actual offset) then zero my X, Y, Z. If I were to lose power and need to restart, I’d probe the corner and execute the same G0 X50 Y50 command to get me back to my work offset. I will sometimes also use the front left corner of my wasteboard for the same purpose, probe it then use G0 X?? Y?? to move to my starting point.

Be careful to keep in mind where your workpiece is when executing the G0 commands, it would be safer to use an order like this to help avoid crashing the bit into the stock:

Move spindle to the top:
G53 G0 Z0
Move spindle to the work offset
G0 X?? Y??
Move spindle to the work offset z height
G0 Z??

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