Bill Schwab wrote:
Darren,

Nothing can be outsourced, and I'd need the tools and know-how for
future projects anyway.

These particular squared holes will be about 1/8" from the
edges(corners) of the stainless steel.

The square holes are necessary because I'm creating a hinge set-up
where I'll need put squared Delrin bushings with round holes through
them into the square holes created in the 1/16" thick stainless steel.
The holes need to be square so that only the rod that will go through
the bushing will turn and not the bushing itself.


Dumb question: do the holes need to be square, or merely have flat
sides? If the corners could be rounded, you could mill windows using a
small-diameter endmill. Cutting SS will make it more fun than simply
milling a window w/o undercutting (which is a good challenge in itself),
but I suspect you could do it. If there is an SS-related problem I am
missing, others will correct the record.

I am a little confused about the rotation constraint. Is there only one
hinge on each plate? If so, it seems very likely to bind??? If there
are two or more, it should not be able to rotate even with round holes.

Funny how things make sense only after pusing the send button - it
sounds as though you are trying to get something to turn, and to hold
the bushing in place. If that's the case, then scratch the two-point
comment, but it seems that a window would work if you are willing to
round the corners of the bushings, or if you deliberately undercut the
corners to make room for the corners of the bushings. The bottom line
is that you might consider doing something simple with the SS that gives
you the same effect as a square hole in it.

Here's a clarification.

Imagine a 4" X 4", 1/16" thick stainless steel plate layed flat with
four stainless steel rods sticking out from each corner.

To accomplish this, I'll have to cut a 1/16" slot in the end of the
rods so that each rod can slide over it's corner of the plate. Now
there will also have to be holes drilled down into each rod *and*
through the plate so I can drop a Delrin cylinder through each of them.

Concentrating on one corner, since the plate which is only 1/16" thick
will over a relatively short time cut into the Delrin cylinder because
of it's turning motion, I have to place a Delrin bushing in the plate
hole first, and the bushing has to be square so that it does not turn.
And if the bushing doesn't turn the plate will not cut into it.

Thanks a lot.

Darren Harris
Staten Island, New York.