Please pay attention to the Spindle Working Speed !
Engraving machine spindle motor may be clearly different than Milling machine spindle.
For engraving machine, the higher spindle speed, the greater cutting force. the lower speed, the smaller cutting force, if spindle speed is too low may be caused spindle stalled or VFD burned.
So, depending on the different materials, set spindle speed to 12,000 ~ 24,000 is most appropriate.
1) ABS/PVC/POM/Nylon and other plastic materials use about 16,000rpm.
2) 6061 aluminum and H59 brass use about 16000~20000rpm.
3) Acrylic use about 17,000~22,000rpm.
Different materials should be more testing.