Re: Electrodes (Re: Tungsten Rod)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Dave Leddon by way of Terry Fritz <twftesla-at-qwest-dot-net>" <leddon1-at-llnl.gov>

Hi Terry,

Actually the rod I was considering is:
http://www.mcmaster-dot-com/param/asp/psearch.asp?FAM=tungsten&FT_128=520&session=tungsten;128=520
which is cheaper than the "high density tungsten carbide rods" at a mere 
$24.24 for a 12 inch rod (to get there from the front page search for 
"Tungsten Carbide Rods and Balls"). This material is available in diameters 
up to one inch which makes me wonder if I shouldn't be considering an even 
larger diameter.  Is 1/4 inch rod meaty enough for a power input of 10 KVA 
at 120 bps on a 3600 rpm rotor?

Thanks,
Dave

At 06:04 PM 12/1/2002, you wrote:
>Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
>Hi,
>
>McMaster-Carr has tungsten alloy (90W 6%Ni 4% Cu) rod at:
>
>http://www.mcmaster-dot-com/cgi/loadpage.cgi?pagenum=3357&catnum=108&forceFormat=PDF
>
>Or try
>
>http://www.mcmaster-dot-com/
>
>and search on tungsten. Its the top ones for "high density tungsten 
>carbide rods"or try to get to page 3357.
>
>They have from 1/8th inch to 2 inches in diameter (for larger coils 
>:o)))  It says it is "machinable", but I imagine it is darn tough!
>
>12 inch long 1/4 inch rod goes for $38.00  12 inches of 2 inch rod sets 
>you back $790.
>
>They "say" the melting point is 2012F (maybe they meant C?) which seems 
>kind of low.  Pure tungsten is 6192F.  I think these rods are made in an 
>odd powered sintered process so maybe the melting point is low.  I could 
>not find melting point information in a quick net search.
>
>The tungsten bare drill rods have very low tungsten content, but maybe 
>that is the material Marc had so much luck with?  That is what they use 
>for cutting tools on page 3359.  With an R/C harness of 44/66, good luck 
>cutting it ;-))  I imagine that is well within the EDM, waterjet, plasma 
>cutting territory, although, a cobalt tipped hack saw may have a small 
>chance.  Cobalt rod I know will just shatter (guess how I know that ;-))
>
>Cheers,
>
>         Terry
>
>
>At 08:16 PM 12/1/2002 -0500, you wrote:
>>Way back Marc Metlicka had some nice tungsten carbide electrodes for
>>sale.  There are pics at:
>>
>>http://www.fortunecity-dot-com/meltingpot/syria/1210/1c120580.jpg
>>
>>Anyone know where to get anything like this?  A bulk buy, maybe?
>>
>>         - Bill Vanyo
>>
>>Tesla list wrote:
>> >
>> > Original poster: "Dave Leddon by way of Terry Fritz 
>> <twftesla-at-qwest-dot-net>" <leddon-at-attbi-dot-com>
>> >
>> > After firing up the old SRSG with a pig for the first time, it quickly
>> > became apparent that 1/8 inch tungsten electrodes just weren't going 
>> to get
>> > it, so I'm now trying to locate a source of ¼ inch tungsten rod.  McMaster
>> > has some tungsten/carbide rod listed but I don't know how suitable this
>> > would be compared to pure tungsten.  Any thoughts or suggestions for
>> > sources and materials would be appreciated.
>> >
>> > Dave
>