It is required to remove 10 mm depth from a workpiece of dimensions 350*100 mm. An end mill cutting tool of 60 mm. diameter and 8 teeth with 30 m/min cutting speed and 0.1 mm/tooth feed is used. Find; a) The machining time (max. depth of cut = 3 mm). b) The metal remove rate. Solution GIVEN:- Depth d = 10mm, Area A = 35000mm2, End mill diameter D = 60mm, Cutting speed S = 30m/min=500mm/s Feed F = 0.1mm/tooth x 8 = 0.8mm, Max depth of cut dc = 3mm SOLUTION:- a) Time required for cutting a length of 350mm & at feed F=0.8mm at max cutting speed = 350/500=0.7s Total cuts required for cutting total area A = 35000/(350x0.8) = 125 So time required for cutting at depth of 3 mm = 125 x 0.7 = 87.5 secs Total time required for cutting depth of d = 10mm = 87.5 x 4 = 350 secs = 5 mins, 50 secs Machining time T = 5 mins,50 secs (ANSWER) (b) Metal removal rate MRR = (Length x F x dc) / Cutting time = (350 x 0.8 x 3) / 0.7 = 1200mm3/s So MRR = 1200 mm3/s (ANSWER).