I made some changes to my MPCNC, found what was causing me issues after a winter hibernation (belts had become much looser on one side than the other), upped my voltage from 12V to 24V, and upped my max Z speed to ~30mm/s.
In ~6-7 hours (6% stepover on 1/8" inch ballnose bit) I turned this:
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Into this:
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Used a cheap 6mm bit (10 for $10) to rough, then a cheap 1/8" ball nose (10 for $10) for finish pass.