Homework Number Four

Due Saturday November 14, 2015 (12 Noon)

1) Using the operations performed in the first machining practica (5^th Week). Explain how you would make the following part shown at the bottom from the stock shown at the top.

2) Determine the power required for the first turning operation in problem 1. Assume that your feed rate is 1.5x10^-3 mm/rev, that the lathe is running at 600 rpm, and that the material has a specific energy of 6.0 J/mm³.

3) A carbide tool is used to part cast iron. If the tool speed is 500 ft/min, the tool life is 60 minutes. If the tool speed is 600 ft/min, the tool life is 20 minutes. How much more expensive (based on tool costs alone) would it be to increase the tool speed from 500 ft/min to 700 ft/min?

4) Consider the desk decoration shown below. Each hole is 1/8” in diameter, and ¼” deep. The thicknesses refer to the how thick the metal is as measured from the bottom surface. Assume this part is to be made from a 4in x 4in x 1in block of cast aluminum. Explain how you would make this part using the processes in the second machining practica (6^th week).

5) Your supervisor is confused because the costs of tool replacement and power are directly related in lathe operations but not in slab milling. Explain this to them.