[eloeffler]

im working in polar interpolation on the sub side of a star sr-20 and weve been trying to figure out the correct way to find the feed rate while in polar....
this is a swiss turn screw machine, im milling on the sub side with a high speed spindle at about 14 thousand rpms, using a 4 flute .055 mill. my smm(surface meteres per minute) is around 200mm(my machines in metric) milling in polar interpolation, this is no longer a linear move, wich to me means i need to transform my meters per minute into degrees per minute via the sub spindles rotation, or "c" axis.

i gues in other words what im asking is,
how do you convert inches/mm per minute into degrees per minute....

[christinandavid]

guesstimate the average diameter you are milling at

diameter x pi = circumference

circumference / 360 = distance per degree

feedrate / distance per degree = feedrate in degrees

DP