carbide, tungsten rods.

To: Tesla List <tesla-at-poodle.pupman-dot-com>
Subject: carbide, tungsten rods.
From: Chip Atkinson <chip-at-poodle.pupman-dot-com>
Date: Tue, 26 Nov 1996 10:41:44 -0700 (MST)

Greetings,

I have been following (somewhat) the discussion on tungsten carbide vs. 
tungsten rods.  Here's my solution that seems to work well for me.

I have my 1/8" tungsten rods mounted in aluminum electrode holders that I 
designed and turned on a lathe.  If you dont have a lathe, you could 
still make them, but they may not look so fancy.  Basically they are 
giant heat sinks/conductors.  I took a piece of 2" alum. rod, turned it 
down to 1" over part of it, and threaded it with 1-8 threads.  I also 
drilled a 1/8" hole down the length of the piece.  The tungsten rod fits 
down the hole and is held in place with a set screw.  The tungsten rod 
just protrudes about 1/8" (3mm).  The whole assembly is cooled by the 
whirling nuts on the rotating disk. You can see that there is a lot of 
turbulence in the disk chamber because there are some pieces of teflon 
tape that are flapping in the wind.

True, the tungsten erodes a little, but I have not lost more than 1-2 mm 
off the tip, and the rods are about 4" long, and not all that expensive 
for their lifetime.

The electrode holders get warm, but not too hot.  I have run the coil for 
perhaps 1 minute continuous at about 2.5 kva (160 volts, 16 amps on my 
meters).  The tungsten never comes close to glowing that I can see.

Chip

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 Chip Atkinson 
 http://bhs.broo.k12.wv.us/homepage/chip/info.htm
 --- Everyone is someone else's weirdo. ---
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