On Sun, 27 Sep 2009 04:03:59 +0000, DoN. Nichols wrote:
On 2009-09-26, Michael Koblic ... wrote:
....
I used to drill similar pieces held in the horizontal v-grove *before*
I cut them off. I tried to let them stick out to the side of the vise
which allowed for proper centering and center drilling. Even then, the
problem was that one had to let the piece stick out quite a bit to be
able to get the chuck down to the piece without the top of the vise
interfering.

Two identical vises, clamping on either side of the area where
you intend to drill.

If you are supporting only at one end, consider that if the
distance from the clamp (vise) to the place where you are drilling is
over four times the diameter of the workpiece, then it will flex. (Same
rule should be used for work held in the chuck of the lathe. [...]

OP 21 Sept 2009, Michael Koblic originally described the problem via:
"I tried to drill a 3/16" cross-hole in a small steel cylinder
(0.3125" diameter, 0.400" length). I clamped the cylinder by the
ends (faced-off and therefore parallel) in a fairly substantial
drill press vise..."

The length of the part, .4", less the hole diameter, .1875",
is .2125, so using two vises for this part would clamp only about
..11" of material at each end. It would be better to make a jig to
hold the part for cross drilling.

The jig would have a horizontal 5/16" hole to hold the part and
an intersecting vertical 3/16" hole for cross drilling.

If the jig were split vertically and hinged at the bottom, it
would clamp the part when clamped in a vise.

If the jig were split horizontally and clamped with vertical
screws or with C-clamps, a hardened drill guide bushing could
be pressed into the top half of the jig, or the jig itself
could be hardened.

If making only a few parts, don't bother splitting the jig, just
drill the intersecting holes and start drilling parts. Once the
drill bit enters the side of the part, the part won't shift within
the jig.

--
jiw