Question: raw materials housing 6 length tubes 2 od tube thickness...
Raw Materials Housing:
6’ length tubes, 2” OD, Tube thickness is 0.065” Spool and Caps: 6’ length rods, 2” OD The raw materials selected are one of the annealed stainless steels (SS) with 200BHN.
Processes Overview 1. Parting housing First step of making the house of valve is to part raw materials (6' tube) into 16'' pieces using saw. Neglect materials removed. Assuming machining time is 1min/cut.
2. Drilling 5 holes on a single housing Parameters for Drilling Drill Bit Size (Inch): 1-7/8; Cutting speed = 200sfpm; Feed rate = 0.006ipr Assume a tool approaching allowance (see the right figure) of half the diameter of the drill.
3. Parting spool Same parting process with parting housing. Part raw materials (rods) by saw. Neglect materials removed. Assuming machining time is 1min/cut.
4. Turning on spool Parameters for Turning Cutting condition: Assume constant surface cutting speed (CSS) will be used. Surface cutting speed = 350 sfpm; Depth of cut = 0.050"; Rough feed = 0.005 ipr; Finish feed = 0.001ipr;
5. Milling on spool A slot needs to be cut into the spool which has not been turned down. Parameters for milling: Feed per tooth, ft = 0.002 in/tooth Depth of cut, d = 0.1” Cutting speed, V = 100 sfpm Tool: HSS Milling cutter of 0.5” diameter, 4 flutes
6. Drilling on spool neck Tool: 1/4” drill bit, 0.125” allowance, HSS Tool Parameters: 0.5” Depth of Cut, 55 sfpm Cutting Speed, 0.004 ipr Feed.
7. Tuning on cap (including cutoff) Same turning parameters as turning on spool. Cut off by carbide insert with 0.25” width. 8. Drilling for the top end cap Drill from 2” diameter face of cap, 1 hole in the center Tool: 1/2” drill bit, 0.25” allowance, HSS Tool Parameters: 0.25” Depth of Cut, 55 sfpm Cutting Speed, 0.007 ipr Feed
Q3. Calculate the minimum tool nose radius required for a surface finish of 180 µinch.