I did see that most posted numbers for RPM on the workbee are much higher than expected - the cutter I’m using has a recommended chip load of .12mm, which results in a theoretical rpm of ~8300 at 2000mm/min - I already reduced the chip load to 0.08mm to account for the fact that the workbee isn’t the most rigid machine, but 18k would mean a chip load of 0.05mm, which to me sounds like getting close to the tool just rubbing - but maybe my expectations are off here, I’m still quite new to this!
If you have some guidelines on how far you generally derate endmills for the workbee, it’d be quite useful to know!
The cut depth is an interesting one though - i didn’t think 3mm with a 6mm endmill would be pushing it, but I’ll try with a gentler finishing pass and see if that makes a difference!