"Ned Simmons" wrote in message
...
On Tue, 13 Sep 2011 09:21:33 -0400, "Ed Huntress"
wrote:


"Spehro Pefhany" wrote in message
. ..
On Mon, 12 Sep 2011 22:12:11 -0400, the renowned "Ed Huntress"
wrote:


"Spehro Pefhany" wrote in message
m...
Can anyone suggest top-notch Euro-zone or Japanese company that can do
ultra-precise (as in measured in nanometers) EDM work in somewhat
exotic materials? Cost is not that important, within reason.

I'm not getting what I need from mold-maker type guys.

Can't use a US source for this, unfortunately, too much in the way of
potential hassles, and lots of money involved.


The only thing I can think of is to call the US executive offices of
Agie,
Mitsubishi, or Sodick, and ask for a contact in their home countries who
can
help. You'll find plenty of English-language speakers at the home
offices
of
all three.

That sounds like a good approach. Ned Simmons also suggested going
through the machine manufacturers. Thanks to both.

Are you familiar with the capabilities of EDM? 25 nanometers is roughly
one
microinch. Depending on how many nanometers you're talking about, you
may
be
a bit outside of the envelope.

Too bad you can't use a US vendor. For exotics and top-notch EDM work,
I'd
recommend these guys:

http://www.njpt.com/ . Ask for Bob Tarantino.

Thanks. There may be some other work we can send them.

They pioneered wirecut EDMing of foamed titatanium and they work in a
variety of superalloys, doing a lot of critical medical-device work.
Just
how exotic is the material you're talking about?

Not super exotic- Nb and Ti pure and alloy.

Hmmm. I wonder if there's *anyone* who has experience EDMing niobium. With
a
melting point of 2477 C (4500 F), that could be very interesting.
Titatnium,
however, is EDMed successfully in various applications.

Anyway, good luck. It certainly sounds interesting. EDMing anything in the
sub-micron accuracy range is a challenge, and probably will require some
testing and experimentation.

It doesn't seem to be a problem. I've designed many tungsten (MP
3400C) and moly (2600C) parts, and never had trouble getting them
EDMed.


Right. It's not that they can't be EDMed (Sumitomo even makes, or made, a
conductive ceramic that can be EDMed), but the speed, settings, overburn and
wire reaction (and deflection) get tricky with refractory metals.
Superalloys and other refractory materials have been wire-EDMed for decades,
but I suspect that pure niobium is a very rare one, if anyone does it at
all.


The fixtures I spoke of in my other post had tolerances down in the
low micron range. In that case the hurdle was not so much the
tolerances as the length and size of the features. The parts have
numerous deep slots as narrow as .040 mm x 25mm long, which requires
running small wire with a relatively large spacing between the guides.
I believe they were being made on Mitsubishi machines.

That one sounds very tough, although, if the wire parh is straight down
those slots, that makes it a lot easier. The wire will bow, or deflect,
quite a bit, lagging in the middle, but it still cuts straight along
straight lines.

--
Ed Huntress


--
Ned Simmons