Page 1 of 1
First gun not launching
Posted: Mon Jul 02, 2007 11:15 pm
by motowater
I just went out to the store today and bought all the parts for a spud gun. I am using axe sprayed in the back of the combustion chamber as the fuel. I hooked the bbq spark plug up to two screws in the chamber, and I do see a spark. The combustion chamber does not even ignite. Does anyone know what the problem could be?
By the way, I used the following design for the gun, except I made the combustion chamber 2 feet long with 4 in. PVC tube, and the barrel is 6 feet of 2 in. PVC tube.
http://www.instructables.com/id/EDFTHMSTCJEQ2W334L/
Posted: Mon Jul 02, 2007 11:16 pm
by wanimal
add a potato? it usually helps me
Posted: Mon Jul 02, 2007 11:18 pm
by noname
You need something in the barrel or all the fuel will leak out. Use a paper towel or something until you get the mixture down.
Posted: Mon Jul 02, 2007 11:20 pm
by hi
im pretty sure he added potatos.....
anyway, most people have the common belief that the more fuel the better, which is totally wrong. from what you described it sounds like about a 1 second spray would work best, you just have to mess with it until you get it right. it usually takes me about an hour to get it perfect, just keep trying and you will get it.
be sure to post it in the showcase area, im sure it cool.
welcome to spudfiles.
Posted: Mon Jul 02, 2007 11:44 pm
by noname
A two foot long 4" chamber should take about 3 seconds of most aerosol sprays to fuel well. An exact two seconds works perfectly in both of my combustions (3" x 12" chambers).
I have to get some ether.....I saw some the other day and the ingredients were Diethyl Ether and four hydrocarbons. Sounds pretty frickin' good!
Re: First gun not launching
Posted: Mon Jul 02, 2007 11:46 pm
by spudkilla
motowater wrote:I just went out to the store today and bought all the parts for a spud gun. I am using axe sprayed in the back of the combustion chamber as the fuel. I hooked the bbq spark plug up to two screws in the chamber, and I do see a spark. The combustion chamber does not even ignite. Does anyone know what the problem could be?
By the way, I used the following design for the gun, except I made the combustion chamber 2 feet long with 4 in. PVC tube, and the barrel is 6 feet of 2 in. PVC tube.
http://www.instructables.com/id/EDFTHMSTCJEQ2W334L/
Hmmmmm, If you bought it today, i wouldn't try to fire it tonight... let the glue dry overnight!
Posted: Mon Jul 02, 2007 11:54 pm
by Big-mac
if you use to much spray it wont work go easy until u get it down
Posted: Tue Jul 03, 2007 12:34 am
by motowater
what do you guys recommend I use as a fuel for this setup? Is axe good, I havent tried hairspray, is it any better?