Description: Z - 0 height gets progressively lower during the cut. I zeroed the machine using the puck. The initial cuts were at the appropriate height, just cutting through the material. As the project progresses, the cuts lowered into the spoil board. After canceling the project I manually found Z - 0 with the paper method. the controller read a zero position of +5.6, indicating that the machine had lost the true 0.
This happened this morning with the new controller.
My project involves lots (100ish) of up and down movements so maybe related.
Things I checked
- Bit Slippage. I marked the bit position with a sharpie. The bit remained in the exact same place relative to the collet.
- one-off issue - i reran the same g code file and was able to replicate the issue. I reexported a new gcode file and experienced the same thing. each time the new Z was between 3-6 mm off.
- Something wrong with the vcarve project or tool paths - I ran the same vcarve tool paths on the small CNC and did not experience the same thing.
I did not make a problem report because there is a not insignificant chance this is user error.