On May 23, 6:06*pm, "Michael Koblic" wrote:
How do you drill cross holes in small cylinders (brass or steel). The
cylinders are 3/8 - 1/2" in diameter and often less than 1" in length. The
hole is 1/4"

I am having all sorts of problems with this: The clamping is limited as the
clamps often interfere with the drill, especially centre drill. I find it
impossible to clamp both ends of the cylinder for the same reason. I tried
drill press vise, v-blocks, side-ways chucks, you name it.

What usually happens is that the part tends to flex somewhat and even if it
does not there is horrible chatter.

Some sort of sacrificial v-block? But the part still has to be held in it
somehow.

--
Michael Koblic,
Campbell River, BC

A perennial project in The Model Engineer magazine was the cross-
drilling jig. Most consisted of an upside down "V" with some manner
of drill bushing and a clamping mechanism for the part. If you want
to spend some bucks, Heinrich makes them and MSC catalogs them. You
need the drill bushing for accuracy, just going at it on a curved
surface leads to wandering and breakage. I have used a crotch center
in the lathe tailstock to do cross-drilling. I had a Jacobs headstock
chuck to hold the bit, I used a center bit to start with and
progressed from there. The work was long enough to hand-hold. Drilled
the hole first, then cut and faced to length and hole position. It was
low-accuracy, but got the job done. Crotch centers seem to have
vanished from the catalogs, I got mine from Sears waaay back.
Basically a round v-block on a Morse taper shank. One could be made
up easily enough.

Stan