Made: Jam Jar Pulse Jet

I’ve been receiving Make magazine since its first issue, so I decided it was about time I actually make something. I picked the Jam Jar Pulse Jet from issue 05 (more info here). This project was really easy — the hardest part was finding the canning jars in Wal-Mart. Here’s the finished product:

And another shot showing the top of the jar better:

One thing that’s not mentioned in the instructions very well is how abso-freakin hot this thing gets. One of the troubleshooting tips is to put your thumb over the hole and shake the jar up to vaporize more of the methanol. I tried to light it once, got only a “whoof” and decided that the fuel needed to be vaporized again. That “whoof” was enough to make the lid hot enough that I got an immediate blister when I stuck my thumb on it. I guess I should have been wearing gloves like the instructions said.

This thing, when you get it working, is amazing. I haven’t had a chance to try it at night yet, so I can’t see the combustion, but the sound it makes is enough to make up for it. I’m going to try to get some video of it in action in the next day or so — you’ve got to hear it to believe it.