Awl --
I built a "riser box" upon which sits a cheapie collet chuck, so's I can face/drill/tap the ends of longish rod in a vmc, instead of a manual lathe -- theoretically up to about 21" long (!!!), but right now I'm doing about 12.5" long, 5/8- 1" dia.
This enables me to face rods to a fairly exact length, which is important in this app, AND get in pretty quick drill/tapping, otherwise laborious on a manual lathe.
Yeah, it's only 1 pc at a time (but so would a manual lathe!), but I have a fixture planned that would do *tablefuls* of these, if shit pans out -- mebbe 50-100 per load.
Inyway,
Using a 3" face mill ( sandvik, 6 sq inserts) on 1" round, I know that with the face mill clear of the material, I can take a cut, and stop while the 1" round is *under/within* the diam of the face mill -- iow, no wasted travel.
The Q is: can I lower in Z while the material is within the face mill underside, and cut coming back out, or should I just come out, lower Z, and cut coming back in? Note that no cutting occurs while lowering in Z.
It seems, from the sound of things, I can't take an aggressive cut while coming back out clear of the material, but is it permissible at all? I don't want to screw up/chip any inserts. Oh, 6061 aluminum, as always.
I figger I might as well get some cutting bang for my moving buck, whilst coming back out.
Now, speaking of cutting *whilst moving in Z*, can you do this with an insert face mill? Initially generating a kind of odd trepan.