Vibration Analysis in High Speed Rough and Finish Millin.pptVIP

Vibration Analysis in High Speed Rough and Finish Milling Hardened Steel Presented By: Peter Cannon October 27, 2004 Agenda Function Characterize chatter vibration effects in high speed milling (HSM) Compare chatter effects for Different cutter path orientations Different cutter conditions Different milling directions (up and down) Different milling processes (rough and finish) Importance Chatter and vibration affect Dimensional accuracy Surface finish Tool Life Spindle Life Chatter creates waste Suggestions needed for optimal cutter orientation in HSM References References Class Relevance The paper investigates relationship between terms introduced in class Chatter Down Milling Up Milling Profiling Paper recommends guidelines for High Speed Milling to improve tool life and operation efficiency Design Definition Cutter experiences dynamic forces in 3 dimensions (x, y, z) Dynamic force signatures for each dimension are collected, and a fast Fourier transform is performed to create a frequency spectrum Frequency patterns can indicate presence of chatter Parameters Down Milling – cutting speed in same direction as part feed (Thick to thin chips) Up Milling – cutting speed in opposite direction of part feed (Thin to thick chips) Rough Milling 10,000 RPM Fpt = .0667 mm/tooth Axial Depth = 20, 25, 10 mm Radial Depth = .5 mm Finish Milling 3,250 RPM Fpt = .1 mm/tooth Axial Depth = .5 mm Radial Depth = .5 mm New Cutter – Flank wear land width .05 mm Worn Cutter – Flank wear land width ≥ .3 mm Design Principle The design principle here is procedural Results will not affect cutter, spindle, or machine design Results will affect design of milling operation, order and aggressiveness of cut, and orientation of cutter Experimental Equipment Material Hardened AISI H13 hot worked steel (HRC 52) HRC 52 Face milled and ground as prep Cutters Tungsten Carbide 6-Flute 10 mm Diameter 45° helix angle -14° radial rake angle (Al,Ti)N monolayer coating 2.5 μm thick Runout 10