According to :

[ ... ]

It would seem to be more reliable(though not easier or cheaper) than
using Delrin rods.

It may well be cheaper than using Delrin rods. After all, these
are mass produced to standard diameters and lengths. Delrin tends to be
rather expensive (though something like 1/8" diameter rods would not be
that expensive, and you would simply have to turn them to the desired
final diameter and cut them to length.

I do have a lot of Delrin that I could probably make as many pins as
I'd need.(Though turning it down to 1/8" of an inch may be asking a lot
of the lathe). :-)

Hmm ... how big is the Delrin to start? Anyway, if you are
turning a length down to 1/8", and the length is something like 9/16" or
so, it *will* bend as you try to turn it. The way to accomplish the
task is:

1) Start with a very sharp HSS tool -- ground to the angles
which are right for turning Delrin. (Note that carbide inserts
are usually a bit too dull to do this job well, though the tiny
uncoated inserts for my Compact-5/CNC tend to be quite sharp
enough. They are hard to find, and are usually quite expensive.

2) Turn only the end-most 1/8" down to 1/8" diameter.

3) Then turn the next 1/8",

4) Repeat until you have enough length to part it off to your final
length.

And -- don't have any more of the Delrin sticking out of the
chuck than you plan to turn for that one part.

[ ... ]

The roll pin expands to fit the hole, within reason. But
without special fixturing (other than the V on the top of a bench
block), I would suggest that you drill through both the sleeve and the
rod at the same time. The hole may wind up a bit off center, but it
will be the same for both parts, so the roll pin should fit through it
easily enough.

What if I used a sharp punch of some sort to start, followed by a
center drill in the lathe, and then drill after that? since the 1/8"
hole is only 1/8" from the bottom I'd probably have to balance things
by using a tube with a 7/16" I.D. to fit over the rod/sleeve,
effectively lengthen it so it would slip out of the chuck.

Hmm ... how do you plan to use the lathe for this? I thought
that the hole was from one side to the other, not into the center of the
end.

If the holes must *all* be the same distance from the end, you
will want a V-block clamped to the drill press table, with a stop to
keep you from sliding the workpiece in too far.

[ ... ]

O.K. Good luck there. There will be things which you will have
to design for yourself.

I already have a couple of tool post mods in mind. :-)

O.K.

Good Luck,
DoN.

--
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 ---