Jeff, the first site is down, but I saw yours, it is awesome. If you placed this thing in a vacuum bell jar, and somehow spun the cubic magnet (some electric field?), it would probably spin almost forever.
i
If push comes to shove, they will work just as well as coal in the fireplace :-)
Mark Rand RTFM
Easy to machine yes but it is rather tough on the tools and it is messy.
When I worked at a mold shop I was drilling and doing the rough machining on graphite and I got filthy. My boss was grinding the electrodes, and before he got his wet grinder, he would emerge from the grinding room looking like a coal miner at the end of a long shift.
A shop near where I once worked made a zinc injection molding machine that used graphite blocks for the molds. He used a zinc allow with very little expansion/contraction and could keep very tight tolerances, major uses were for things like sprockets and gears for food processor lines.
Graphite molds used to be used in thermite welding of grounding conductors to ground rods and structural steel. These have mostly been replaced by single use ceramic molds. Gerry :-)} London, Canada
Arc electrodes for electric furnace?
I'm not so sure about the "nothing sticks to it". As I do glassblowing I have been told that molten glass will stick to graphite if you get the graphite too hot. I believe that is around red heat. I have recently done glass casting into graphite moulds preheated to 400C and didn't have any problem with the glass sticking though.
The German V2 rocket nozzles from WW2 where graphite. Must have worked OK.
>
Next time something like this comes up you ought to have your grandson involved in the process.
If you do, he will know how much work it is, and he will learn how it was done. During the process you guys get a chance to talk, and after the process you can talk about the time value of the process.
This was another of the those neat posts where many of us can learn something!
I drilled a pair of 2 X 2 X 2 inch blocks and fitted them around a 1/2" shaft to use as a ground connection for a rotary welding table.
Pete Stanaitis
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Ignoramus1197 wrote:
That graphite combining with the steel might form some interesting metal.
John
WWII searchlights used carbon arc lamps, and in the mid 70's I worked at a cinema that also owned a Drive-in theature that used carbon arcs for the projector.
No they won't. Graphite doesn't burn under normal conditions.
That's possible.
Too much work to convert raw carbon into an electrode - they used a round rod with (afaik) special additives blended in to get the proper color temperature for the purpose, and then the rods were copper plated for conductivity to the rod holders and advance mechanism.
But for drive-in theatres and very long throws with big follow spots, and other uses where you need over 10K of light in a small package, they still make more sense than Xenon Short-Arc projection lamps. They have only recently upped the power levels available in discharge lamps.
Disneyland still uses carbon-arc Strong Super Gladiator follow spots for Tinkerbell's nightly flight, because they need a lot of light to work with a 600' throw.
And Valley Skylight still rents out old WW-II Sperry and GE aircraft searchlight rigs for special events, and the old Chrysler Industrial straight-six flatheads in the gensets keep chugging along...
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