Question

You are given the following specifications for raw material: hollow barstock, 5.125 in. O.D. X 2.25 in. I.D. X 5.0 in. long. You must machine the piece to the following dimensions on a CNC lathe with constant cutting velocity: 4.750 +0.000/- 0.001 in. O.D., 2.750 +0.001/-0.000 in. I.D. and length of 4.75 +/-0.002 in. All of the tools have a nose radius of 0.031 in. and allow a maximum depth of cut of 0.125 in. The workpiece material must be machined with a cutting speed of 500 sfpm and a feedrate of 0.012 ipr. Calculate: a) total machining time for the facing operation b) total machining time for the boring operation c) surface roughness (Ra) for the boring operation

Answer 1

Given spec hollow bar shụ.ç.asîn.。. D.x2-25 ; ona o 02 ips Given outer dia 5.1 -o Oo) Lnner ナU-00 2. Leng Fime depth of cut 0-/25- 2

t- 4323 0-3220 ± o-O0615 hun OTAJ line二 九 0.3220土0.0000ド n der Tme kaken for bon 2-25. in duced n: no-chats-dia to he 12 TX 2.25メ 二0-012 91-0-03) 0.000193