On Sunday, March 6, 2011 6:12:43 PM UTC-8, Snag wrote:
Karl Townsend wrote:
Got a tuff little job for tomorrow morning...

I'm making a new end of an air cylinder. Start with a 3.5 by 3.5 block
1.5" thick. Center and turn in the lathe so you now have a 2.5" round
protruding 0.25".

Now for the tuff part, turn a groove 0.062" wide on the face right at
the 2.5" round.

The groove is right at the base of the cylindrical part ? Can you put the
block on a rotary table , mill the round , change to the appropriate end
mill to cut the groove ?

It sounds like that puts a little (.062") end mill, with a shank no larger,
into over a quarter inch of trouble. The endmill finish at the bottom
of the groove is gonna be bad for sealing, too, unless you have
some kind of finishing cut in mind.

I'd think in terms of a boring bar held (near) transverse to the lathe axis, with
its tip doing this work. In mass production, make a holesaw for the
right radius, and many teeth will make light work of the task.