Question about MeshCAM Keepout

I have a design that involves cutting a pattern out of an 8" x 8" x 0.2" piece of plywood.

With previous experiments, I’ve found that fine detail designs like this don’t work when holding the stock to the wasteboard with tape/glue, because if it’s held firmly enough to cut the design, it’s impossible to remove the work from the wasteboard after cutting without breaking it.

I’ve designed this new project such that I could bolt the stock directly to the table. My idea is that I’ll use bolt down two pieces of stock, cut the top one (while using the bottom one as wasteboard).

The thing I’m worried about is whether excluding an area in MeshCAM actually prevents travel through that region. If I have bolt heads sticking up 0.25" from my stock, I don’t want any rapid moves passing through that “airspace” above the stock there.

In MeshCAM I set the bolt areas as “keepout” and the preview does show no machining happening there, but rapid moves do pass through those areas. Is there a configuration I can be using to prevent this, or is this basic strategy of bolting the stock down a non-starter?


the retract height setting is handy for avoiding cutter to bolt interaction.

Thanks Mark. Is that what’s used when it’s generating gcode for the rapid moves?

It is one of the settings in meshcam that will tell the machine to lift the tool a bit higher on retracts and thus, you can fly over the bolt if by adding some margin to what it suggests.

Excellent! Thanks for the pointer.

I’ll post results here when I get a little further along.

I can confirm Mark’s point—that the setting you’re looking for there is the retract height, and in some CAM packages there’s a “clearance height” also, which is the height the tool should travel at when not over the stock so it doesn’t hit other stuff in the work area (like clamps/fixtures). By using the machining regions and the retract height you should be able to keep it out of your fasteners quite well.

Remember, it’s asking for height above stock, not height above model, so make sure not to mix those up!