Feed rates for peripheral milling with circular interpolation are programmed for the
centerline of the cutter. When milling in a circular path, the cutter edge is feeding at a
rate different than that of the cutter centerline. The following formula is used to
calculate the chip per tooth:
Inches/Minute may be substituted for Chip/Tooth in the formula. In that case the result
would be Inches/Minute and the calculation of IPM would not be necessary.
The programmed Chip/Tooth multiplied by the rpm of the spindle and the number of teeth in
the cutter will give the Inches/Minute to program for the feed rate. Feed = Programmed
Chip Rate x rpm x Number of Teeth
In the case of staggered tooth tools, divide the number of flutes by two.