Milling Forces Measured With a Planetary-Gear Torquemeter

Cutting-force data, obtained with a torquemeter of planetary-gear design in carbide milling tests on SAE-1018 cold-rolled steel at feeds from 0.002 to 0.030 in. per tooth, cutting speeds from 87 to 957 fpm, and depths of cut from 0.100 to 0.300 in. with a tool geometry of −7°, 0°, 3°, 5°, 0°, 15°, 1/64^″ × 45°, are presented. The influences of variations in cutting speed, feed per tooth, and depth of cut on tangential cutting force are depicted graphically. Cutting-force values for other workpiece materials are also included. With these data a comparative method of experimentally verifying the computed high efficiency of the torquemeter itself is derived and applied. A method of obtaining highly accurate determinations of milling machine efficiency under actual oscillatory cutting loads is described with an example. Actual and theoretical traces of the variation of tangential cutting force with both single and multiple-toothed face milling cutters are illustrated for comparison.