What can cause this problem? Most of the letters I’m cutting have a ring around them where the material was not all cut out. This happens with both inside and outside cuts. It’s almost like when the tool makes the finishing cut, the rough cut wasn’t big enough. I’m using a 1/8 inch end mill, and the settings are 10mm feed rate, .75 mm depth of cut, and 45% stepover.
See the picture for an example.
Thanks for any help!