Get spindle speed and feed rate for a CNC router bit cutting wood, MDF, or plastic, from bit diameter, target surface speed, chip load, and flute count.
RPM = (SFM x 3.82) / D. Feed = RPM x chip load x flutes. Wood and plastics tolerate much higher chip loads than metal, so use chip load values meant for the material, not metal cutting charts.
How it works
Router spindles are usually fixed-speed or limited to a narrow RPM range, so it is common to pick the closest available RPM first and then solve for the feed rate that delivers the chip load you want at that speed.
FAQ
My router only has a few speed settings, now what? Plug in the closest RPM your machine actually offers instead of the calculated one, then adjust the feed rate until the resulting chip load matches your target.
Related Guides
CNC Calculators · SFM Calculator · Chip Load Calculator