GATE 2016 ME (ME2) – Question 34

Machining and Machine Tool Operations · Machining operations, machine tools, cutting tools and tool geometry · 1 mark · Numerical answer

The following data is applicable for a turning operation. The length of job is 900 mm, diameter of job is 200 mm, feed rate is 0.25 mm/rev and optimum cutting speed is 300 m/min. The machining time (in min) is __________

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Correct answer: 7.4 to 7.6

Explanation

Spindle speed is N=1000V/(πD)=1000·300/(π·200)=477.465rpm. Axial feed speed is fN=0.25·477.465=119.366mm/min. Machining time is900/119.366=**7.54minutes**. No approach or overtravel allowance is specified.