Eliminating negative space on final pass

Hi All
I’m using MeshCAM for a 15” diameter sign. I have 1/8” raised letters, a man on a fishing boat and then 1/8” recessed water lines and a sky above pine trees. I will make my final pass using a 1/16” ball mill. How can I tell MeshCAM to not go over the negative spaces, meaning the spaces that don’t include the above parts I described? If I can do this I know I can take hours off of the finishing pass.

Hi Jim,

Since no one has offered you specific advice on MeshCAM yet - I will just suggest you look for a way to make a boundary around the areas you do not want to machine ( or a boundary around the areas you do want to machine - it depends which is easier ).
I have not used Meshcam but have used 6 other cam packages to date. They all had ways to make these boundaries to restrict the cutter movements to specific areas.
I did a google search and here is a link to the meshcam faq talking about boundaries.

How do I control the area to be machined?