Nomad 3 milling slot & hole oversized

I’m having an issue with my Nomad 3 and perhaps someone in this forum has a solution.

I’m trying to cut a 1/8” slot using a 1/8” flat end mill to do so. I’ve set up a pocket toolpath on a rectangle .1255” wide and 1” long (if the rectangle is exactly .125” wide I get an EMPTY TOOLPATH error). When my Nomad cuts the pocket it is .140” wide, not .125 to .126 in width. If I use a 1/16” cutter same thing happens. In order for me to get a 1/8” slot I must reduce the size of the rectangular slot to .110” and use the 16th inch cutter. This doesn’t seem right, my Nomad is cutting an oversized slot. This also occurs when I cut a hole, its over the size of the hole I want. Is this a software error, machine error or human error? Maybe someone else has experienced this and has a fix? The fix I’ve come up with is not very elegant.

Thanks for any feedback,

Is it possible to post the posted code of so we can read it?


One option for dimension critical things is to cut them undersize, then measure, then adjust the CAM file to cut to the desired dimension.

Have you measured the size of your cutters?
Does the machine make multiple passes in the slot (to make it wider then the cutter)?
If you want a slot exactly the diameter of the cutter then you can use contour rather than pocket.

1 Like

Hi Craig,
Here is the setup I have.
slot ,1255 wide.c2d (44 KB)

Yes, the cutter is .123" diameter. Yes it makes two passes. I tried contour and got the same results.

Essentially I measured the slot that was oversized on scrap material then reduced the slot width by the appropriate amount to get to the target dimension.

1 Like

I am not a Nomad expert but they have the same basic electronics as a Shapeoko. Maybe you need to calibrate your machine. Basically you cut some circles and squares and measure them for accuracy. If they are off you can edit your stepper motor steps to fix the problem. It is likely something else but you should at least cut some circles and squares and make sure they are the size you make them and bigger or smaller. That will help separate an accuracy problem from mechanical/electrical.

Not sure it can be calibration if a contour (single pass) is oversized. If a contour is oversized then it must be material tear out or spindle runout.

1 Like

The code reads correct for the #102 end mill. The software does not seem to be the problem. (usually never is) If you have not already, try removing your end mill and collet from your router, inspect and clean both the collet and router spindle bore. Use a Qtip with a bit of IPA for the spindle bore. Lets’ make sure there is no damage or debree causing run out. Maybe feel the spindle nose for any motion from a worn bearing. Then as @flynnjs said, make a single line cut and measure the slot to test for run out. Do this at precise location to you can check for location accuracy. If that’s good, try what @gdon_2003 is suggesting, a circle, diamond, square test. Again at a precise location.

1 Like

Definitely agree that you should check what diameter of slot you are cutting w/ the tool, and adjust your cutting diameter to match that.

Also, leave a roughing clearance and make a finishing pass.

Might not be helpful, but try the cut in X and in Y directions. If the runout or deflection is causing this it might be lessened if the deflection is in the same direction as movement?

Of the z gantry bends towards you as it naturally would when loaded downwards into the material it might open wider at the top just from being slightly angled compared to the stock.


This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.