On Feb 23, 7:19*am, Karl Townsend
wrote:
On Wed, 23 Feb 2011 03:53:37 -0800 (PST), "Denis G."
...
To do the ID, I'd probably use a Unibit on the drill press. *Instead
of using super glue, I think that I would capture it in the lathe
centered between two pieces of sacrificial stock. *One piece held by
the chuck and the other piece held in place with the pressure of the
tailstock. *Clamp the sheet metal piece between them, and then turn
the OD.

2nd that. I'd use a 3/4 bolt and two washers as the arbor and
sacrificial metal. Put several nuts on the bolt to hold in the three
jaw chuck.

I was thinking of drilling and boring the hole first too, maybe in
square sheared blanks stacked and clamped to a faceplate under a
washer. Then they could be sheared / chiseled / sawn close to a
scribed OD line.

You can center drill the ends of a bolt and run it between centers to
cut a precise work-holding step in the underside of the head. If you
turn down the threaded end to fit a collet the arbor can be removed
and replaced easily and you don't have to fuss with a driving dog. The
driving leverage is poor and the collet can slip so take light cuts. I
suppose a 3-jaw would work as long as it doesn't force the tailstock
center hole out of line.

I use the next larger nut or a big socket as the spacer.

jsw