Is this going to wreck my mill?

[stephen thomas]

Nothing i would not cut on my 30 taper mill.

If set up as shown, with a lot shorter arbor, per implmex.
Or better yet, inverted in a pair of angle irons (safer/more stable than the vise set up for second op)

Set up inverted, i'd cut the clearance/"neck" hole first - takes a lot of stress off the under cutter, and it maintains location, so you don't have to set part up twice.

At that point, i'd put the shell mill on an arbor that would fit the neck slot or less, and come back in like a T-slot cutter. If the shell mill does not have clearance on the top (& you don't want to spend some time on a T & C to correct that), invert it on the arbor with suitable spacer, and run the mill in reverse.

If done the way you show, the part gains only a little support being fully in in the vise. Balance it with a same width block, but hang the projection out. Now ues an EM or other cutter to bore and chop out the slot incrementally mill the slot with up/down feed before a finishing milling pass. (or take small depth milling passes to a stop set on the mill table. Either way to minimize deflection from the overhang) Then mill the relief without losing position. Preferably still with a shorter arbor.

smt

 

[BT Fabrication]

Thx, will tell the apprentice no gloves around rotating stuff. I’ll post a pic of the OKK older Japanese mill, my favorite mill in the shop. It is 10 hp. Never have found a manual for that MH 3V-II Model but there’s a metal lube chart on the side, the important part of the manual for me.

to be honest, gloves are good and bad, as the operator needs to be super aware to never go anywhere within 1 ft of the rotating part. And the only reaction should be turn off the spindle power or e stop and never try to grab anything. its all a calculated risk machining anything.

i use them, but never to grab a part while the spindle is turning. turn it off and grab it when its crazy hot, sure. id rather not burn myself. or have them turning handles as the chips are stupid hot to land on bare skin and melt into it.