I was making an arbor for a Norton aluminum-oxide 4" cup grinding wheel from
mild steel using the Clausing 5914 Lathe, and had a minor misadventure.

The stock is a 2.5" diameter 12L14 alloy bar held in the 3-jaw chuck. The part
I was working on is 1.000" diameter by 2" long, sticking out to the right where
the 2.5" diameter bar has been turned down. There must have been two pounds of
chips in the pan by then.

Anyway, I'm making a near final pass under relatively slow power feed using a
BXA-16N toolholder, and the flat full face of the carbide insert comes up
against the machined end face of the bar. Instead of machining the face a
little flatter, the whole BXA tool post rotates on the compound, causing the bit
on the BXA-16N to dig a bit deeper. There were no groans or loud noises, but
still this is not a good idea.

Anyway, I realized what was going on, and managed to stop the show before
anything bad happened, leaving only an undercut as evidence.

Another lesson on the way to becoming a machinist.

Joe Gwinn