3D print molten metal in space. Duh.

They have crazy pencil sharpeners in Russia.

Grither: They have crazy pencil sharpeners in Russia.

They need do way instain sharpeners who kill thier penncils.

Way, way back, I found a book full of radio-frequency heating projects. It had projects for building an induction heater like this one, and a plasma torch as well. Difficulty: everything ran on big honking tubes, fed from big honking transformers, and I was an all-solid-state kinda guy.

I'm sure they could redo the book with today's big honking MOSFETs, but I'm not up to designing it myself. I'm also not really up for homebrew projects that can reach across several inches to deal sudden, smelly, charred death.

I did see a demo of this once in high school, and it was indeed way cool. The little copper-tubing coil wasn't very impressive, but the four-foot-on-a-side metal cabinet it stuck out of was.

I remember waking up early on School mornings to watch Mr. Wizard on Nickelodeon. Ahhhh, those were the days. Had the experiment books and everything.

On one episode, Mr. Wizard used a starter pistol to demonstrate the speed of sound. I doubt that would be allowed in today's zero tolerance world.

jfarkinB: Way, way back, I found a book full of radio-frequency heating projects. It had projects for building an induction heater like this one, and a plasma torch as well. Difficulty: everything ran on big honking tubes, fed from big honking transformers, and I was an all-solid-state kinda guy.

I'm sure they could redo the book with today's big honking MOSFETs, but I'm not up to designing it myself. I'm also not really up for homebrew projects that can reach across several inches to deal sudden, smelly, charred death.

I did see a demo of this once in high school, and it was indeed way cool. The little copper-tubing coil wasn't very impressive, but the four-foot-on-a-side metal cabinet it stuck out of was.

Forget redesigning circuits or using big honkin anythings. You want good, cheap induction heating, go back to the tried and true (and fun) methods. :)

Well, it's a bit of a stretch to call microwaving "inductive heating", but okay -- if that was really transferring energy directly to the melt metal, I guess it counts. Real inductive heaters run at much lower frequencies, though, I think.

jfarkinB: Well, it's a bit of a stretch to call microwaving "inductive heating", but okay -- if that was really transferring energy directly to the melt metal, I guess it counts. Real inductive heaters run at much lower frequencies, though, I think.

It's a half-stretch. Heating food via microwave is done through a different mechanism since food is generally a shiatty conductor. Generally speaking though, any oscillating mag field within any metal will cause inductive heating. And microwaves are already designed to crap out a couple kilowatts of E&M.

Although now that I think about it, in the microwave you're also going to get incident electric fields causing direct conductive heating. So it's a 3/4 stretch. But that last 1/4 is allllll induction, baby! (And yeah, real induction heaters are usually lower freq.)