Meshcam Pro X,Y, Z-Axis zero vs Shapeoko Pro5 X,Y, Z-Axis zero


I have some questions about this topic:

In MeshCAM Pro I see an XYZ origin arrows on the top right corner of the 6" square x .75 Thick blank.

MC: I set the stock to the blank dimensions for a simple contour cut 6" x 6" x .75".
CMo: Load program.
CMo: States load tool, resume.
Pro5: BitSetter, Sets tool Z.
CMo: Move X & Y to corner of Blank. Then I set Z to touch top of blank. Set all axis to ZERO in CMo menu.
MCo: Starts
Pro5: Moves to a different X,Y, Z origin.


  1. What is the correlation between the ZERO origins in MC and Pro5?
  2. What information is the PRO5 Bitsetter sending which relates to any program?
  3. How to have the ZERO origin the same in MC and Pro5 in relation to the work blank?
  4. How is the data from the Pro5 BitSetter used in MC/Pro5?

Thanks for any explanation and help understanding this.

Post post your .mcf file and let us know how you are setting zero (a photo showing machine position, and a screen grab of the Set Zero page).

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The BitSetter does not set your zero. When you initialize a set of internal coordinates are recorded. Then when you physically set the Z zero an offset is made. So when you are prompted for a tool it travels over to the BitSetter and new offset is created for that bit which sets the Z zero position that was last set with the BitZero or a manual method. So the BitZero is keeping track of where the Z zero was set and makes an offset to properly position the new bit at the same height as the last bit. Typically when we replace bits they are never inserted at the same height as the last bit.

Most importantly is never change a bit manually if using a BitSetter. Only change a bit when prompted by your gcode sender or through the software interface of CM to change a tool. When you manually jog and replace a bit you lost the synchronization of the internal coordinates and the BitSetter Z zero.


So as I understand it from your post. Once the BitSetter sets the first tool Z zero any tool changes forced by the program in CMo compares the first Z zero with the second Z zero and adjusts the difference between the two zero offsets and sets a new offset for the second tool. This now makes the second tool to the same Z zero offset as the first tool.

Is this all independent of any other programs zero but CMo?

Thanks ~KAP

Yes. Correct.

Carbide Motion after setting the machine origin after initially homing will then calculate Z-axis zero relative to that position based on the measured length offset of the current tool.

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Just to be clear. When you have the BitSetter checked in configuration, during initialization you are prompted for a tool, any tool. The internal coordinates set during initialization remembers the offset from the LAST time you set Z zero which may have the last time you set z zero a week ago. The X Y and Z zero positions are persistent over power cycles with the small caveat that the initialization triggering can be a few thousands off each time you initialize. The proximity switches are pretty good but not perfect.

So if you set the Z zero that is remembered by CM and stays as long as you do not rezero Z. The BitSetter is simply making a new offset with a new tool based on the previous offset made during the last setting of Z and the initialization.

So before doing the JOG in CMo to the work-piece XY corner, CMo prompts to put in a tool and run the BitSetter. After doing this one can JOG to the XY corner of the work-piece and then set the Z to touch the top of the work-piece. Then on the CMo JOG screen one can then ZERO out all the XYZ axis.

This should then set the XYZ corner in CMo to the same XYZ in MeshCAM, correct?

When running the program and it prompts for a tool change BitSetter just looks at the difference between the two tool Z points and makes the corrected offset so it is back at ZERO again.

I think I am understanding it some ~KAP

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