Thanks Kirk -
These aren’t traditional PCBs where you need to clear copper around traces. These are what’s called Manhattan Style, where I am carving lines to create islands of continuity that I solder parts directly to. So all I really need to do is carve a bunch of straight lines through the copper. Any CAD software should be able to do it safely. At this point I don’t think the issue has anything to do with Carbide.
I tried the same cut on MDF and it turned out perfect. It seems the issue is the bit deflecting when it contacts the copper.
Thanks for input on the spindle upgrade, SainSmart sells it as a direct drop-in replacement for a SainSmart CNC. I found the ramp-up G-code example on their web site. Be nice if they included note in the package.
Dean