One year ago a machine was purchased at a cost of $2,000, to be useful for 6 years. However, the machine has failed to perform properly and has a costs of $500 per year per year for repairs, adjustments, and shutdowns. A new machine is available to accomplish the functions desired and has an initial cost of $3,500. Its maintenance costs are expected to be $50 per year during its service life of 5 years. The approximate market value of the present machine has been roughly $1,200. If the operating costs (other than maintenance) for both machines are equal, show whether it is economical to purchase the new machine. Perform a before-tax study using an interest rate of 12%, and assume that the salvage values will be negligible. 2.

solve question 7

The following data were obtained from a time study performed on a horizontal milling machine: Average manual effort time per cycle: 4.62 minutes. Average cutting time (electric feed): 3.74 minutes. Average performance rating: 115%. Backlash due to machine (power supply): 10%. Slack due to fatigue: 15%. What is the standard time for the operation?

In a production operation, a high-speed steel face cutting tool with 8 cutting edges is used for the face milling of a rectangular workpiece with dimensions of 650 mm length x 120 mm width x 100mm thickness and 4 J/mm3 specific energy of cutting. The cutting tool has a diameter of 60 mm and is cutting with a rotational speed of 500 RPM and a chip load of 0.1 mm/tooth. If the part thickness is to be reduced to 95 mm using a 5 mm depth of cut and a width of cut of 40 mm, then find the following; a) The total time (min) to machine the workpiece b) Material removal rate during the cut c) The power (kw) consumed while the tool is engaged in cutting of the workpiece d) The Cutting force Fc