3. Taylor is selecting a tool for a turning operation, and is considering using disposable inserts.

The turning operation feed is 0.3 mm/rev. Taylor tool life equation parameters for the desired

tool grade are n = 0.25 and C = 300 (m/min).

For disposable inserts, the price for each insert is $6.00, and there are four cutting edges per

insert. On average, tool change time takes 1.0 min. Machine time on the lathe costs $24.00/hr.

The work part to be turned requires a 400 mm long cut and is 65 mm in diameter. It takes

2.0 minutes to load and unload the part.

Determine

a) cutting speed that will allow Taylor to achieve the lowest per part cost, and

b) tool life under those conditions (minimum cost).

(10 points)

(5 points)

(5 points)/n4. Alex needs to order stock material to make 100 cotter joint sockets (Fig. 2). The aluminum

bar available from the supplier is provided in Fig. 3. The cut-off saw has a kerf of 0.3 inches.

In addition, 0.15 inches must be removed from both faces of raw stock where saw cutting

occurs to generate a square blank from which the part is to be machined. (The stock surface

finish will be acceptable as-is, but the saw cut will not.)

(20 points)

a) Given the available choices, which stock size (length, width, thickness) would you choose

to evaluate?

(4 points)

b) Calculate the number of pieces of stock you would need to order for each of the choices

you indicated in Part a.

c) Calculate the total material cost for each stock size you indicated in Part a.

d) Calculate total stock waste volume for each size you indicated in Part a.

e) Which stock size will you recommend purchasing? Explain your reasoning.

(4 points)

(4 points)

(4 points)

(4 points)