So I'm working out of my house right now. Mostly doing computer work, but so of it is designing things for someone to build in a lab elsewhere. I recently decided to make a few things out of foam and ship them rather than try to explain what I have in mind over the web. So I built a hot wire foam cutter.

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All it is is a piece of wire with a voltage across it so that it heats up hot enough to cut foam. An RC airplane guy gave me that the idea. So I built one. It's a lot of work to someone like me that's not particularly good with handtools. I even went out and bought a plastic mitre box and managed to still not cut straight.

For the wire, I spent $10 on a hair dryer and took it apart. I figured the wire should be the right kind of wire and the power supply on the end of the plug should not only do the job, but be better than anything I'd go spec out on my own. So I take it all apart and wire it as I see fit and it doesn't work. There are a handful of electronic components, so I try various combinations wasting a lot of time...no dice. So I go back to the store and buy a multimeter. I take some measurements and go online and figure out how these things are supposed to work and have to make another trip to radioshack to buy power resistors to make up for some of the changes I've made. Finally the things works.

***resume reading the short version***
I go out to another store to buy some foam...and guess what my wife spots on the shelf? A commercial hot wire foam cutter. $15.