CNC Services Northwest

Method 1: Use a dedicated reference tool

Use this method if you have several tools you wish to set up, keep, and reuse, but you do not have a consistent tool measuring surface (e.g. on a knee mill, or measuring on stock surface).

This is the method described in Centroid's Basic Training video.



Preparation (one-time)

  1. Cut a piece of drill rod, about the length of your longest tools.
  2. Grind or turn the end smooth, for consistent measurement.
  3. Put it in a tool holder, where it will remain permanently available.

Operation (for each job)

  1. Load all of the tools for the job into their tool holders.
  2. Go to the offset library: F1/Setup -> F2/Tool -> F1/Offsets
  3. Put the Reference Tool (the drill rod) in the spindle.
  4. Jog to touch off on some convenient surface.
  5. Press F1 to set Z Reference.
  6. Press F10 to set Z Reference here.
  7. For each tool in the job:
    1. Highlight the tool/offset number.
    2. Load the tool.
    3. Jog to touch off on the surface.
    4. Press F2 to measure the offset.
  8. Press F10 to save the measured offsets.
  9. Go to Part Setup: F1/Setup -> F1/Part
  10. Touch off and set X and Y positions normally.
  11. Touch off the part surface with whatever tool happens to be in the spindle.
  12. Enter the correct Tool Number, then press F10 to set the Z position.

If you have to replace one tool

  1. Go to the Offset Library: F1/Setup -> F2/Tool -> F1/Offsets
  2. Set Z Reference from any convenient surface, as you did before.
  3. Load and measure the new tool off the same surface.


When measuring a replacement tool, you do not have to use the same surface you used to measure the other tools, as long as you reset Z Reference off of the new surface before measuring the new tool.

If the previous tool measuring surface has remained unchanged (e.g. you measured the tools off the vise jaw, and have not moved the vise or knee), then you can measure replacement tools off that same surface without resetting Z Reference. Z Reference remains valid as long as the measuring surface does not move.

Copyright © 2017 Marc Leonard
Last updated 15-May-2017 MBL