Regarding high speed toolpaths and coolant
I've been running faster and harder every day with HSMA and wanted to pick your brain for a minute regarding a set of parts I ran a couple days ago.
The material is A2 Tool Steel 230HB, big solid chunk held very securely so I can go like a stabbed rat.
I was cutting using a .360 4FL Var Helix AlTiN Coated End Mill (no corner radius) that was .875 LOC and sticking out 1 inch.
I've been experimenting with going to slightly lower WOC to take advantage of HSM and chip thinning operations. I was at 10% (.036) WOC and .750 DOC cutting at 7334RPM and 106IPM. This was insane fast, and the cutter made it through 3 slots that were 3.5x2.0 with life to spare.
The problem came with HEAT building up in the part. The first one I cut dry, the chips were blue and had nice crisp edges under the microscope. The part, however, got VERY hot to the touch, to the point that there were a few marks left after a 0.005 finish pass (it didn't move in vise, so must be heat expansion?). I ran the next 2 with coolant and they cut fine, however I wasn't letting the AlTiN get up to temp.
Would the proper solution be to go back to the heavier WOC with lower speeds and feeds to get a heavy chip to take more heat? This seems correct, but I am kind of addicted to the speed now.
Sorry if this is outside the scope of the forum here, but I figured it'd be an interesting discussion to have with you. I appreciate your time and effort as always. :ernaehrung004: