A work piece 400 mm x 70 mm in diameter is to be machined. The material has constants n=0.23and C=250 m/min. Disposable tools costs $6.00 (4 cutting edges per tool), tool change time is 1 min. Regrindable tools cost $35 each (used 12 times) and tool change time is 3 min. Reginding time is 5 min and the grinder costs $25/hr. Cost of operator and machine tool is $50/hr, time to load and unload work piece is 2.0 min, and feed rate is 0.3 mm/rev.
Find: a) cutting speed for minimum tool wear, b) machining time, and c) the total time and total cost per piece for both types of tools