MeshCAM: Cutting width question

Hopefully a quick question: if I am trying to cut a valley into a project, for example something like acrylic where all I really need to do is mar it, what is a rule of thumb for how narrow I can make a cut based on the diameter of my square endmill? I have run into a problem with meshcam a couple times where it just ignored cuts I had in a project, I assume it was because it was fairly narrow for the bit. .01 wide cut with a .008 dia bit.

If it matters, Designing in AutoCAD into MeshCAM.

Thank you.

@imp, as long as you use a .0001" calculation tolerance you should be able to make a .010" slot using a .008" bit. I use the rule of thumb 10% larger slot than bit. But the calculation tolerance is the critical factor. A looser tolerance, and the larger slot width minimum for the same cutter size. It’s independent of CAD, strictly an aspect of MeshCAM.


The general rule is MeshCAM does not “see” a feature that is less than 10% larger than the end mill diameter. This is true when the tolerance is 0.0001".

When roughing, there is material left over. That gets added to the number above. This is often why small features are not roughed.


Ahh, there it is, I had my tolerance set to .001". Added a 0, and now meshcam is seeing everything. Thank you both.

How about Carbide Create? Does the same 10% thumb rule apply?