I have Delrin of Different shapes, but I'd use the scraps which are
basically about 1-1/2" x 2.00" X 12". I'd take it to a band saw first
to make it manageable for the lathe to turn down.

You are going to be making a lot more chips than parts, starting
from that size. A serious bit of waste in my book. And, you *will*
need the 4-jaw independent chuck to hold those rectangular pieces.

Yes. I'm thinking a 5" chuck with a spindle bore that is at least .787"
would be preferrable.

Hmm ... look at the MSC web site:

http://www1.mscdirect.com/CGI/NNSRIT...PMT4NO=4749765

which shows 1/8" Delrin (acetal) rod, 1 foot long, for 98 cents each.
Your choice of black, or natural (fairly white). Hmm ... that looks
like Teflon (PTFE), not Delrin (acetyl).

At 98 cents, that's obviously the better way to go. I'll save the
Delrin scrap I have for something else.

I'm assuming that Delrin would be the best choice as far as plastics,
but my first choice is your idea to use the roll pins. It would seem
that they would withstand shearing forces better.

[ ... ]

Thanks. from what I've read, I should treat Delrin like Stainless steel
as far as the sharp tool and cutting speeds.

I also have several 4" diameter Delrin cylinders that are about a foot
long, I'll be slicing them into 3/16" or 1/4" thick disks that I'll
need to do six plunging operations involving making different sized
holes/slots in each of six equal "pie" slices.

O.K.

BTW. If there is a way to do this using my lathe, the drill would have
to be at the headstock end, and I'd need something like a six-sided
collet block in something not only large enough to hold a 4" disk, but
also position it at varyng heights above the bed.

So obvious a drill press and a rotary table would be the easiest and
cheapest way to go for this.(I'd have to "overlap" drill holes to make
slots).

Now. yes, the 11/16" long(7/16" diameter) sleeve will have the turned
down end of the rod already inserted into it so I can drill the 1/8"
diameter hole all the way through *both* at the same time. That 1/8"
diameter hole will be located only 1/8" from the end, so gripping it so
it could be drilled would pose a problem.

Hmm ... I would not bother with the center punch given that
setup, as long as the holder (fixture) which you describe below remains
fixed in position between workpieces.

Yes. I'd ahve to make a dedicated face palte and holder just for this.

As I say -- the punch probably is not necessary. Just start the
hole with the center drill. (You can get them down to 1/8" diameter,
which would make a great start for the hole.

Yes. I believe that would be the #1 center drill.

Ok. If a $50 drill press would be easier then I will get one.(Hopefully
better than my last one).

Your setup on the faceplate would work. But you would need to
add a counterweight on the faceplate to allow it to balance properly so
you could run at reasonable speeds for a 1/8" drill bit.

Hmm... My original thought was to drill out the solid end of the
holder(a little at a time) which at the start would be slightly heavier
than the side holding the work and Aluminum block. until the weight on
both sides of the center axis(drill point) was equal. This would be
determined by balancing the center axis on a straight edge. But if this
is a bad idea I'll entertain your suggestion.

Thanks.

Darren Harris
Staten Island, New York.