After I began my project, I decided it was not cutting to the depth that I wanted. I need to change cutting depth, which I know how to do, I just don’t know how to get it to start over in the same spot with the adjusted cutting depth.
Same for switching bits mid-cut. How do I get it to start over in the same spot if I pause it to change bits?
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if you do not use a touch block (i.e. three corner like the Triquetra from @CharleyThomas) then you need to make a start point off and away from the project so that you can restart from that point. some times I make a mark with the bit or burn a spot with the laser, so if this happens I can restart from the original start point. if you do not have such a point then you will have a very difficult time to get it right on track.
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There are a few ways to achieve this, with or without homing switches.
With Homing switches installed and enabled:
1 - At start-up of machine perform a Homing Cycle
2 - Jog to material start point and set Z height
3 - Alter the carve depth in design and use this new gcode for 2nd run, in Easel simply click Carve → Use previous home position
4 - If you have changed tool there is only one step more that need to be done and that is re-zero Z.
5 - Home position is stored as an offset of Machine Home (machine zero) and position is saved even between power cycles.
Without Homing switches:
1 - Skip first point above
2-4 still valid
5 - no machine zero known, stored offset can be anywehere since there is no machine reference.
Another approach that I have resortet to on occation where more depth was required and not wanting to look at the CNC do a lot of air carving to get past previous depth:slight_smile:
Say I have a 4mm pocket and did 1mm depth per pass, then decided I needed 6mm total depth
I set depth per pass for 2nd carve = 5mm which will prompt the first pass to occur 1mm below previous depth, with 1mm to go which will be the 2nd pass.
Whaaaaa? Home position is stored even after power cycles? Meaning if something fails mid way then I can choose use last home and it remembers? I never tried that assuming that since it required a machine home with each cycle that it didn’t remember that. I also use jigs and g28 command to go back to work home. I’ll have to try this out.
Yes it is, work zero (home position) is stored, until a new work zero have been set. 
Note that the stored position (work zero) is an offset from machine zero so you need a fixed Machine Zero. Which is what a homing cycle/homing switches provide.
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Yesterday I was engraving the Triquetra Logo on top of a batch of touch plates. After they were all done I removed the jigs I used for alignment only to realize a while later after applying the blue ink that some of them were not deep enough and when I removed the excess over spray, they looked terrible. Stored positions are of no use without my original jigs in EXACTLY the same spot to reference from. A disaster for sure, but perhaps not. I remounted my jig and not in the same location for sure. I only need to make sure it was aligned with the machine travel. The inserted a touch plate blank that had already been engraved. I re zeroed with my Triquetra Touch plate and ran the engraving tool path again with the correct depths. When done there was absolutely no evidence of the issue. This is a true story that actually happened yesterday,.
Charley
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These were not completed in this picture. They still needed to be drilled for the banana plugs and have the cut’s cleaned up. But rest assured, they are spiffied up and in need of a good home now!!
Thanks so much for the clarification. I totally thought the opposite and this will save me a lot of time.