You are the manager of a workshop. You need to turn 1,500 shafts as an intermediate...

   

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You are the manager of a workshop. You need to turn 1,500 shafts as an intermediate step in a larger manufacturing process. It takes your workshop technician 20 min to machine a single shaft at a cutting speed of 15 m/min and 10 min to set up the blank in the spindle. Since you are turning 1,500 shafts, the technician will certainly change the cutting tool to maintain quality - a tool change would require five minutes. The technician's hourly rate is QAR 350 per hour; your overhead cost is 200%. A local supplier sells you the blanks at the cost of QAR 250 per unit. The process has been traditionally done using a high-speed steel (HSS) cutting tool- these tools are available from a local supplier at the cost of QAR 10 per tool. A HSS cutting tool would provide high quality surface finish for 1 hour of cutting at the cutting speed of 15 m/min and then would need to be changed. However, to make (time and financial) savings, you want to investigate using a carbide cutting tool that the supplier offered to you at QAR 50 per tool. This carbide cutting tool would provide high quality surface finish for 6 hours of cutting at the cutting speed of 15 m/min. 1) Calculate the cost of machining the 1,500 shafts at the nominal cutting speed of 15 m/min for both cutting tools. 2) Assuming the same feed rate, how many tools will you use at 17.5 m/min for both the HSS and carbide tools. Notice that a higher cutting speed will lower the tool's life. You can use Taylor's tool life equation: V7 V to find the tool life at a cutting speed of 17.5 m/min. In this equation, V is the cutting speed, T is the tool life and n = 0.125 for HSS and 0.25 for carbide. 3) Calculate the total cost to your workshop for machining the 1,500 shafts: a) Using the HSS tool at 15 m/min (which is what your technician is doing now) b) Using the HSS tool at 17.5 m/min c) Using the carbide tool at 15 m/min d) Using the carbide tool at 17.5 m/min Tabulate your results so you can present them to the head of your business unit (highlight the biggest savings): Cost (QAR) Cost (% Change Time % Change] HSS at 15 m/min HSS at 17.5 m/min Carbide at 15 m/min Carbide at 17.5 m/min NA NA You are the manager of a workshop. You need to turn 1,500 shafts as an intermediate step in a larger manufacturing process. It takes your workshop technician 20 min to machine a single shaft at a cutting speed of 15 m/min and 10 min to set up the blank in the spindle. Since you are turning 1,500 shafts, the technician will certainly change the cutting tool to maintain quality - a tool change would require five minutes. The technician's hourly rate is QAR 350 per hour; your overhead cost is 200%. A local supplier sells you the blanks at the cost of QAR 250 per unit. The process has been traditionally done using a high-speed steel (HSS) cutting tool- these tools are available from a local supplier at the cost of QAR 10 per tool. A HSS cutting tool would provide high quality surface finish for 1 hour of cutting at the cutting speed of 15 m/min and then would need to be changed. However, to make (time and financial) savings, you want to investigate using a carbide cutting tool that the supplier offered to you at QAR 50 per tool. This carbide cutting tool would provide high quality surface finish for 6 hours of cutting at the cutting speed of 15 m/min. 1) Calculate the cost of machining the 1,500 shafts at the nominal cutting speed of 15 m/min for both cutting tools. 2) Assuming the same feed rate, how many tools will you use at 17.5 m/min for both the HSS and carbide tools. Notice that a higher cutting speed will lower the tool's life. You can use Taylor's tool life equation: V7 V to find the tool life at a cutting speed of 17.5 m/min. In this equation, V is the cutting speed, T is the tool life and n = 0.125 for HSS and 0.25 for carbide. 3) Calculate the total cost to your workshop for machining the 1,500 shafts: a) Using the HSS tool at 15 m/min (which is what your technician is doing now) b) Using the HSS tool at 17.5 m/min c) Using the carbide tool at 15 m/min d) Using the carbide tool at 17.5 m/min Tabulate your results so you can present them to the head of your business unit (highlight the biggest savings): Cost (QAR) Cost (% Change Time % Change] HSS at 15 m/min HSS at 17.5 m/min Carbide at 15 m/min Carbide at 17.5 m/min NA NA

Answer rating: 100% (QA)

SOLUTION 1 Cost of machining 1500 shafts at the nominal cutting speed of 15 mmin for both cutting tools For the HSS cutting tool Machining time per shaft 20 min includes 10 min for setup and 5 min for ... View the full answer