A gamer's hands can get pretty sweaty in the heat of battle.(But I'll
have to settle for 303, since no one makes 316* 1-3/8" diameter ball
knobs).

What is wrong with the black Bakelite knobs which are also
available with cast-in brass inserts with female threads for screwing
onto your shaft? They are a bit lighter than the stainless steel, and
certainly a lot less expensive.

Yes, but they wouldn't give it that solid, heavy, durable, quality look
and feel that a stainless steel ball-top would. :-)

O.K. Loctite can be unscrewed -- if you heat it up with a torch
first.

That would be a pain. And since this sleeve will be wedged against a
(3" diameter)Delrin plate I don't think that'll work.

You are obviously not familiar with a roll pin. Picture a
length of flat spring steel stock which has been rolled into a two-turn
roll. The ends are tapered a bit to make them easy to start, and they
are driven into the mating holes, with the spring expanding to grip both
the parts. They can be driven out as long as the hole goes all the way
through. They are available for relatively little money for large
quantities. With blind holes, people have managed to use a tap to
thread the ID and give a grip with a screw to pull them out.

It would seem to be more reliable(though not easier or cheaper) than
using Delrin rods. So I'll look that up. (Tapping is going to be a
subject unto itself that I'll have to study).

The largest workpieces will be A) 4-1/2" square(6" diagonal), 3/16"
thick, and B) 4" square, 1/4" thick.

O.K. It could require somewhat over that 6" diagonal, if the
groove has to be around a point other than the center, because it *must*
rotate around the center of the groove to be.

The groove(which would have a 3" O.D.) would actually have to be made
in the 4" square piece.

I'm actually *considering* using
5052 Aluminum.(6061 would be my second choice).

Given the size of the workpiece, I don't expect too much flex
from 1/4" thick aluminum, let alone SS. :-)

Well, if I go with Aluminum, most of it would be turned/milled down to
1/16" thick. Only a ring(with an O.D. of 2-5/8") would be left. (And a
3/8" Delrin ring(with "cups" drilled into it for the bearings) would
fit around this.

In fact the above may just be the best idea.

What you are looking at are designed to hold flat workpieces and
feed the tap in truly square to the surface. Your rod, with a hole in
the end, would be difficult to mount truly vertically so the tap is
guided in square.

Let me try an ASCII drawing of the kind of tap wrench that I'm
talking about. You'll need to set your screen to a fixed pitch font
like Courier to keep the drawing from being distorted.
__________
___________________/ ________ \_____________________
(___________________ |__ __| _____________________)
\__________/

I clicked "Fixed Font" on this Google page and it was no better than
proportionate. But when I clicked print to bring up the printer
friendly page your ASCII drawing came out perfect.

I was looking at those tap wrenches on the Grizzly catalog, so I'll
have to investigate further what I'll need to drill that 1/8" diameter
hole through rod and sleeve.

BTW. I suspect that the 11/16" long sleeve(tube) would be easier to buy
than to attempt to drill a rod that length end to end.

But be careful to not loose circulation in your legs with that
big catalog on your lap.

:-) I tried getting a catalog from them a couple of months ago with no
luck. Even though they advertsie the catalog, there are no options for
getting it.(My Grizzly catalog just arrived though).

Did you phone them?

Did you register with them? (They give you a customer number to
use in subsequent orders.)

Is it possible that they delivered one and it was stolen? They
normally send the catalogs via UPS, same as the parts which they
sell. (Though the last catalog came via USPS instead, IIRC.)

Or -- do you have a lazy mailman? One who won't deliver
anything which does not fit in your mailbox?

Or -- it might just be that they're out of that catalog, and the
new one is just about to be printed and shipped.

I'll try again.

The diameter that I'll have to drill through is 7/16"(which would
actually be the total of the rod inside the sleeve together).

O.K. A small benchtop drill press (perhaps $50.00 or less from
eBay to get a junky one, but one which you can carry upstairs in one
hand. It may be sloppy, however.

Obviously "small" and "accurate" don't go together on any of these
machines.

Nope -- though they do on ones like my Cameron Micro Precision
sensitive drill press. It is a maximum chuck capacity of 1/8" with the
Albrecht chuck, though a small Jacobs 3/16" chuck can be fitted to the
drill press. It is precise enough so it handles #80 drill bits (Hard to
see, even in the drill index) with no problems.

I believe I'v seen simular drill presses go for $400+ on eBay. Anyway,
I can only hope that one of the $50 bench tops will allow enough
accuracy for my needs. I suppose I'll need it to be pretty accurate if
I go with the roll pin.

My wording probably wasn't clear enough. Basically, I'll need to turn a
4-1/2" square(1/16" thick) plate into a 3" disk that has four 1/2" wide
arms that are rounded at the ends.

Hmm ... Do they need to be a full 180 degrees of rounding, or
just a gentle curve. The latter can be turned in the lathe. The former
will take either a rotary table, or a larger mill with a corner rounding
end mill.

Technically, I can leave this piece pointed at all four ends, but I
just wanted to clean things up. I'm flexible, so I'll see what can be
done.

I'll still need to get a rotary table, so I'll be searching the
internet for a visual on anything relating to a rotary table on a lathe
that has a milling attachment.

I've never seen such a combination. It is something which you
will have to make up out of parts which you can find and combine
together. A lot of machining is making special combinations of existing
tools. So -- you are highly unlikely to find such a visual. This is
one of those "figure it out for yourself" tasks.

Yes. That is why I joned a Yahoo Group "mlathemods - Mini Lathe
Modifications". Perhaps there will be some ideas there.

BTW. I have a line on an Enco lathe that is supposed to have a lot of
tooling for $550. The seller says he thinks is a 9" by 16", but I don't
know if that even exists. I've only been able to find references to a 9
X 20(#308-0338).

Thanks.

Darren Harris
Staten Island, New York.