How to drill a cenetered hole in end of solid rod

Several years ago, I saw a c-frame tool set up with a laser shining on
the skin at the location of the center of the bottom die. This
simplified aiming for a hole when the die was covered by the skin. He
also rigged up a sledge hammer with a system of ropes and pulleys so
that he could raise the hammer by pressing a lever with his foot, then
let it drop on the punch. This allowed him to have both hands free for
handling a large sheet. We called it a laser guided sledge hammer. It
was not an elegant arrangement, a duct tape and bailing wire affair, but
it worked.

Del Rawlins wrote:

On Sat, 16 Oct 2004 11:52:02 +0000, Scott
wrote:


I need to make a specialized tool and am looking for a way to drill a
1/16" hole EXACTLY in the center of the end of a piece of say 1/2" of
3/4" solid aluminum rod. In other words, I am trying to make something
similar to a screwdriver using solid aluminum rod for the handle and
1/16" brass rod as the blade.


I dunno how exact you mean when you say exact, but this summer I built
a "C-Frame" riveting/dimpling tool and had to drill a 3/16" hole in
the "exact" center of a 5/8" rod. I accomplished this by finding a
piece of 1" or so round steel, clamping it in my drill press vise and
then clamping the vise to the drill press table. I first drilled a
3/16" hole completely through the 1" round steel (approx 2.5" long) as
close to centered as I could (non critical), and then chucked a 5/8"
bit in my drill press. Taking care to keep the alignment the same, I
then drilled about halfway down the first hole with the 5/8" bit to
make a drill guide.

I clamped the 5/8" rod in a vise, and placed the guide over it. Then
took the 3/16" bit in a hand drill and drilled into the rod using the
guide to center it.

It isn't as exact as using a lathe would have gotten, but it is more
than good enough for the task at hand especially considering that I
dont *have* a lathe. A picture of the C-frame tool (before paint and
sandblast) can be found he

http://www.rawlinsbrothers.org/bhfaq/imptool.html

It didn't occur to me to take a picture of the drilling guide but it
should be fairly self explanatory.


================================================== ==
Del Rawlins--
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I think it will be quiet around here now. So long.