On 2010-12-18, Ned Simmons wrote:
On 18 Dec 2010 06:25:36 GMT, "DoN. Nichols"
wrote:

On 2010-12-16, Chris Wilson wrote:
I need to make a fair number of 6 mm OD stainless steel pins to take 1 mm
OD R clips. I want to drill the rods near one end with a 1.5 mm hole for
the R clips. I have a Bridgeport universal mill


I'm not familiar with R clips, FWIW.

AKA hairpin clips.
http://fasteners.hardwarestore.com/1...s--607526.aspx


Aha! The holes are transverse not centered on axis. Forget my
suggestions, then -- other than perhaps the speed suggestions.

...

It really calls for a small lathe -- and likely something like a
Taig or Sherline might get the speeds right. And I know that the Taig
has a spindle available for WW series collets, which are commonly
available in metric sizes in 0.1 mm steps.

A lathe would be more appropriate for axial holes. The OP needs radial
holes.

Agreed. A nice small sensitive drill press would be a good
choice here -- for example the ones made by Cameron Precision. (Except
that they have gone way up in price since I got mine for $149.00 back
around 1972 or so.

And given that you are drilling into a curved surface you will
probably want some kind of drill guide. A simple one, if you are
holding the workpiece in a vise, is made by using a lathe to drill the
same size hole through the center of some stock of the same diameter,
part it off, put the workpiece horizontally in the vise, and lay the
parted piece on top like a checker, tighten the vise, and drill through
using the existing hole as a guide. You probably should put some shirt
cardboard (cereal box cardboard, or something similar) between the
moving jaw and the workpiece and "checker" to prevent slipping and to
adjust to slight differences in diameter. (Replace it often as it gets
crushed, of course.)

A good drill bit for the task would be a high cobalt steel screw
machine drill bit (shorter, thus less flex) with a split point (doesn't
generate as much wandering force so it starts on center better, and it
cuts to the center instead of mashing material out of the way like the
standard chisel-point drill bits tend to do.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---