quote:

Originally posted by slivers:
I've been a job shop machinist for 41 years. I'm half owner of job shop. I, also, have a gunsmithing degree from an accredited 2 yr. gunsmithing program, acquired during my "younger" years. I know the difference between climb cutting and conventional milling. I've, also, got sense enough to not try to cut to size in one pass. I cut an octagon and fluted several barrels while in school. But, we used a hortzontal mill. That set-up was alot more complicated than what I have in mind. Cutter geometry is a mite different between a cutter for a horizontal mill (or the equivalent mounted on a stub and used on a vertical mill) and a cutter normally used on a vertical machine. Yes, VMC means vertical milling center, that abreviation has been used for years. A 4th isn't required as a manual dividing head will work just fine. Make a pass, back the supports away from the barrel, index, move the supports back into position, cut another flat 180* from the last one. Should take less than 8 lines of G code, written on the shop floor, instead of ???????? if I set-up the 4th. I wasn't looking for complete instructions. I thought my question was a simple one directed at those who had cut an octagon on a vertical mill before, be it a manual machine or a VMC (vertical milling center). I guesss not! By the way, I'll climb mill on my finish pass, probably .010", for a finish that'll take less draw filing (hopefully!).