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Posted for "sqpilot@earthlink" <sqpilot@earthlink.net>:
Ed Anderson wrote:
> A number of places, Earnest
>
> But, probably the best one locally is a hobby shop. They generally
> carry those very small type drills.
>
OK. Hungate's. Do you need a special drill press? The way I break
1/8" bits, I know I'll never get a hole in anything denser than bread
with a bit that thin.
I have found that it is best to start the hole with a small center drill.
These little beauties have a very short (approximately 1/4" long or less)
drill on the end, and that expands into a 45 degree countersink. Because of
the short drill length, the drill does not "walk" like a longer drill bit
has the tendency to do. FWIW. Paul Conner
[Seems to me you were talking about drilling a .035 or .040 hole... .035 is a number 65 drill, and .040 is a number 60. You can get either one from a machine tool supplier, or a hobby shop as well. The center drill that would do this job would be a number 0 (zero), as it has a minor diameter of 1/32", or .03125. These are also available from a tooling supply outfit (MSC, McMaster Carr, Enco, etc). Whatever you're drilling with this little guy, you'll want to lock it in a vise to keep it from moving and drill with a drill press. The angle on the countersink is 60 degrees, BTW, but that doesn't matter, as you only need to contersink a couple thou to accommodate either of those drill sizes. Run the RPM way up there (800-1000), and peck away at the hole with light pressure, drilling maybe no more than twice the thickness of the drill bit before backing out and clearing the chips. Use lots of WD40 if you're drilling aluminum and be patient, you'll trouble your way through the part in pretty short order. (I have a package of teeny center drills in my milling machine tool cabinet, turns out they're only #1, too big for your purposes, as their minor diameter is 3/64. If I had the right size I'd have sent you one. Sorry.)
<Marv> ]
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