Solve Problem 22.8, except that the machine tool con-trols operate at a constant cutting speed by continuously adjusting rotational speed for the position of the tool relative to the axis of rotation. The rotational speed at the beginning of the cut = 40 rev/min, and is continuously increased thereafter to maintain a constant cutting speed.

Problem 22.8

The end of a large tubular work part is to be faced on a NC vertical boring mill. The part has an outside diameter of 38.0 in and an inside diameter of 24.0 in. If the facing operation is performed at a rotational speed of 40.0 rev/min, feed of 0.015 in/rev, and depth of cut of 0.180 in, determine

(a) the cutting time to complete the facing operation and the cutting speeds and metal removal rates at the beginning and end of the cut.