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Re: an interesting mechanical engineering problem
Original poster: Stan <wsmg@xxxxxxxxxx>
How about some Tweco welding cable connectors(brass)? You could grind
them so when soldered into the tubing they would be facing straight
at each other making it easy to assemble. Then you could have your
supports on each side of the joint bolt together to hold it all tight
. If you could mount one of the connectors so you could some how
rotate it they will lock in making a even better connection. I know
they make 400 amp but I think they go higher then that. Just a thought!
Tesla list wrote:
Original poster: Tom Perigrin <tip@xxxxxxxxxxxxxx>
At 08:56 PM 1/9/2007, you wrote:
Original poster: Mike <megavolts61@xxxxxxxxx>
You can't get cheaper and simpler than some saw cuts and
(save your time and money for the IGBT's)
Although I'm a big advocate of going cheaply as possible, I'd have
a problem with the visual asthetics of this idea when spending
thousands on what is a showpiece.
More than that... consider the power going through the coil.
Consider what happens if those saw fingers only contact the next
section of pipe at a few places, with a little copper oxide in
between the two layers of copper metal, giving a resistance of 1 ohm
for each joint. The current flub through a joint of 1 ohm and 10
square mm is going to be "fun". Also, as the copper heats it will
oxidize even faster, giving us the sort of problem we see with a
poorly fitting terminal on a car battery. Heck, I've seen that sort
of problem with the poorly made plug on my Chinese Air Conditioner...
after 1 year of use I unplugged it and was scared to death by the
amount of carbonization evidenced around the prongs.
I'd suggest getting a plug and socket made for each joint. The plug
and socket would consist of a 4" OD taper by about 12" long. These
should be accurately turned to be +/- 0.001 (or better). Then, get
them gold plated with at least 0.005 of 24K gold. Also, there
should be a mechanism like a pipe union that snugs the joint
together. Clean the joints with warm soapy water before each
use, and make a protective covering for transport. That's not going
to be a lot of gold..
Sound like MIL-SPEC ? Yeah, probably... but when you are working
with something like this, it's better not to screw it all up by
trying to save a few bucks on such a critical part.
Failing that, I liked the previous suggestion of Stainless Steel
inserts... those can be wire brushed with a brass brush before
assembly to assure there is no oxidized layer contributing
resistance. I don't think you should use copper on copper, unless
you implement a strict protocol of having each joint thoroughly
cleaned and degreased before each assembly.