I had this problem where the bit plunges very deep in the stock, it started a few month ago while I’m still using the z-belt drive, so I decided to upgrade into z-plus, after the upgrade I still have the same problem , I’ll attach a picture
I do have a BitSetter and I use it for changing the tools, the retract height is 0.2000 in.
when it plunges in the wood there is no abnormal sound comes from the z-axis stepper motor
Did you just upgrade to a Z-Plus and this is the first job run with the new upgrade? If yes I’m wondering if you may need to push the configuration back to the controller selecting the proper machine and Z-axis (ie. Shapeoko with Z-Plus), just a thought.
Does this problem happen every time or occasionally?
How do you set your Z-zero (manual, or BitZero v1/v2)? If using the BitZero, do you zero “corner”, or “just z”? If “just Z”, is the probe on top of the work piece instead of overhanging the corner? That one tripped me up a few times, if zeroing just the Z the probe has to be on top of the workpiece or the Z gets messed up by enough to cause what your picture shows.
After zeroing, if you jog the bit over the work piece and jog down to Z=0, is it at the right height?
This issue happens every time I start the machine and attempt to do some engraving or pocketing, so to avoid this I replace the work piece with scrap and run the Gcode. I use Bitzero v1 for probing, but if I’m engraving I zero the XY and Z in the middle (using toolpath zero at center in job setup ) using piece of paper, and for pocking I probe the XYZ with Bitzero.
When it happens now I unplug the “brick” transformer from the wall, turn on the machine wait a few min. Plugin and start again. I don’t know why this happens or why it clears the issue. It has solved my issue a time or two or three.
For BitSetter users, the most common cause for this plunging is arbitrarily putting a new bit into the machine.
There are only two situations where you can put a bit into the router:
When the machine is turned off
When there is a prompt on the screen asking you to do it
There are no other times.
The most common “wrong” time is probably replacing the bit when you are jogging to set up the zero as its easy to think “I’d better put the right one in now so I zero with the correct bit or probe pin”.
I don’t understand why it is so difficult for the OP to itemize the process he uses on the BitSetter so we can stop guessing at a solution and at least eliminate that procedure.
There’s really no need to test it. It’s sort of a law.
If, no matter what your motivation or rationale might be, if you put a bit in router and there is not a prompt on the screen telling you to do it, you will corrupt the Z axis.