Advanced Hydrogen Mini Combustion Cannon

rcman50166 · Wed Feb 06, 2008 8:27 pm

This is a new concept I'm trying out. I'm using metered hydrogen (optional oxygen) as the fuel source. I have a fuel cell producing hydrogen and oxygen. Which stores the hydrogen in a syringe. When the syringe is full it manually injects the hydrogen into the chamber at a ratio of 12 to 1. There isn't a sparker yet so I don't have any damage pics or even sure it works. I plan to add a sparker in the future along with a chamber agitator. The agitator does the same thing as a chamber fan but the agitator will fit in the chamber unlike the fan.

(3/12/08 )Edit: Eureka!

It works! After tinkering with the fuel mixture I got it to what is pretty damn close to the golden ratio. The gun is a monster! It tears through soda cans (a baseline test for me) and shatters the bbs upon impact. I figured out that adding oxygen to the mix made it too rich and wouldn't combust. Using atmospheric air the oxygen percentage is less making it closer to ideal combustion mixtures. The only thing I need to improve now is make the chamber smaller. This will make it so that I can use pure oxygen in the chamber instead of having half the chamber filled with atmospheric air. There is bad news, however, which is I currently don't have a working digital camera so vidoes and pictures are currently out of the question.

jon_89 · Wed Feb 06, 2008 8:34 pm

cant wait to here how it works. can you explain the fuel cell?

elitesniper · Wed Feb 06, 2008 8:34 pm

ah yes be careful with that cap it may shoot out at you due to the small bore barrel, nice mini though.

Killjoy · Wed Feb 06, 2008 8:40 pm

The fuel cell looks like on from those little hydrogen powered cars. Looks cool, but watch it, that bottle might not take the pressure to well. I would suggest remote firings first.

bigbob12345 · Wed Feb 06, 2008 8:47 pm

That looks like a fun little gun but I agree with killjoy remote fireing at first but I wouldnt even expect it to survive the first fireing but if it does youll have a nice little mini.

rcman50166 · Wed Feb 06, 2008 8:49 pm

The cap is what I'm most worried about. But I'm pretty confident with it. Iv'e seen it done before with even larger pill bottles. (Centrum value size) Theer is little to no pressure in the chamber itself. The syringe itself expands to hold the volume of hydrogen. The other output on the hydrogen side goes to the chamber but when filling it a hose clamp is closing the path to the chamber, forcing it to the syringe. When full the clamp is opened and you inject the hydrogen from the syringe, through the fuel cell, and into the chamber. All pressures are ambient.

thespeedycicada · Wed Feb 06, 2008 9:06 pm

but still hydrogen and oxygen has a bit more "oompf" than hairspray so be careful.

Velocity · Wed Feb 06, 2008 9:23 pm

Nice... but I think that you would do more justice to that expensive fuel cell if you put in on a nice mini instead; it would probably have to be around the size of JSR's pen-gun project.

OuchProgramme · Wed Feb 06, 2008 9:46 pm

Bad idea...hydrogen is a VERY VERY VERY powerful gas.

IMO, just stick to propane.

FeLeX · Wed Feb 06, 2008 10:22 pm

OuchProgramme wrote:Bad idea...hydrogen is a VERY VERY VERY powerful gas.

IMO, just stick to propane.

Hasn't some one established that hydrogen+oxygen is less powerful than propane+oxygen.
It would be cool to make a pistol using this type of technology and maybe make it kinda of semi auto.

DYI · Wed Feb 06, 2008 10:34 pm

Bad idea...hydrogen is a VERY VERY VERY powerful gas.

IMO, just stick to propane.

Ah well, people talking out their asses is quite funny in my opinion. In terms of energy released per volume of gas, propane is more powerful than hydrogen. Hydrogen does have a higher burn rate, and I really wouldn't recommend it for any kind of brittle plastic chamber.

Would it really kill you to use a steel chamber? It would cost about $5, and you'd never have to worry about it breaking.

OuchProgramme · Wed Feb 06, 2008 11:46 pm

FeLeX wrote:
OuchProgramme wrote:Bad idea...hydrogen is a VERY VERY VERY powerful gas.

IMO, just stick to propane.
Hasn't some one established that hydrogen+oxygen is less powerful than propane+oxygen.
It would be cool to make a pistol using this type of technology and maybe make it kinda of semi auto.

Back to what DYI said.

Hydrogen has a fast fast combustion rate, which would basically shatter the plastic.

jon_89 · Thu Feb 07, 2008 1:50 am

Would a gun the size of Jacks pen gun be powerful with hydrogen though? It would be cool though to have something so small and compact.

Do you have the specs for the fuel cell?

flamerz14 · Thu Feb 07, 2008 4:14 am

OR... go build a hybrid with that fuel cell. i mean, come on, you have hydrogen and oxygen. Just need a little bit of metering thats all

rcman50166 · Thu Feb 07, 2008 6:27 am

Well I'm trying this cannon without oxygen injection. This will make it a little less powerful. The bottle is slightly flexible and thick. It's actually surprisingly thick. The perfection combo, I think, kinda like a spring is to metal. The fuel cell is a slow charge fuel cell. It takes about 15s/mL. It wouldn't be practical for anything larger than this. I have a larger one which charges at a rate of 1mL/s. Even that is impractical for the average spud gun. The fuel cell required would have to be at least 20mL/s. Plus look up the pringles can hydrogen experiment. A pringles can can survive a combustion I'm sure this will hold.