OT: Sheet metal and UNF screws (was Re: PET and the IEEE-488 interface)

[Pete Turnbull]

On Apr 1 2005, 20:33, Philip Pemberton wrote:

> It's not supposed to be flexible - it's for the electrodes. Two
pieces of #6
> (5mm dia) copper wire, with one end ground down to a 1/32 rounded
point.

OK, that makes good sense.  Try Folkestone Engineering Supplies, a
company I've used for small amounts of "stuff".  They have no minimum
order and they just happen to have some 1/4" copper (your #4 is just a
little smaller than 1/4"):

http://www.metal2models.btinternet.co.uk/Copper.htm

Have you got a lathe?  If not, I'm not far away if you need the ends
machined.

> I can see two possibilities - either the 2.5mm wire will work fine,
or it
> will blast itself apart when the capacitor array dumps 50-odd (or was
it 70?
> need to crunch the numbers again) watt-seconds through it.

I'd guess the electrodes won't be very long, and the pressures won't be
very high for this spot welder, but 2.5mm might also bend.

-- 
Pete						Peter Turnbull
						Network Manager
						University of York