Hairspray (rather off-topic)

[Tim]

A video of a potato cannon my son and I built last week and tested yesterday:

http://opencircuitdesign.com/~tim/videos/

Built from the instructions in the book "Backyard Ballistics".

Just to show that with a suitable combustion chamber, Suave "extreme hold" (which I use on my heated bed plate, and swear by) is also "extreme release". The potato cannon was primed with a 2-second shot of hairspray, ignited using a flint sparker for camp lanterns.

[Jules]

Cool! Never heard of a potato cannon.

[Slipshine]

you can safely use wd40 as a propellant and the threads dont get sticky.

[jimc]

man i made one of those when i was a kid with my friends. my one buddy had one of those old wooden garage doors that he decided to shoot. blew a hole right through it lol. his mom wasnt happy.

[insta]

I used oxygen & butane on a small one (2" combustion chamber, 1/2" barrel) and I shot a rubber-tipped nerf dart clean through an empty box of kitty litter. It made a neat quarter-sized hole in the front and back of the box, which is not weak cardboard on those things.

It was also one of the most terrifying things I've ever done. I'd do it again with a gauntlet and better face protection

[Matt_Sharkey]

3D printed potato gun anyone?

(its a terrible idea, don't do it.)

[Tim]

Actually I was thinking of 3D printed potato cannon parts---leave the functional parts in PVC pipe, but print a nice grip for it, make it look like an RPG launcher or bazooka or something. . .

[Mark the Greater]

make it look like an RPG launcher or bazooka or something. . .

You almost have to.