Phantom tool paths?

[WillAdams (William Adams (Carbide 3D))]

How are you setting zero?

The 1/8" discrepancy sounds a lot like probing a BitZero for only Z, when it is positioned for XYZ, see:

Using/verifying the BitZero

Here is how I check out the functionality of the machine/BitZero: first check that you have sent the correct Z-axis configuration This can be easily done by jogging down to the wasteboard surface, setting zero, then using the Rapid Position command to lift 6mm above the current zero — measure how much the machine moved — if it’s wrong: go to the MDI and send $$ and check that the Z-axis steps/mm match your machine setup: Belt-drive: 40 Z-Plus: 200 HDZ: 320 ​ ​c.f., Then, clamp a sui…