SpudFiles

I'm working on my next cannon that I plan to make sort of like a artillery cannon/bazooka (bipod legs on the barrel extend to different degrees like a mortar tube, or can be hand held by handles/pistol grip). I was wondering if it would be possible to use gasoline as the fuel source instead of just using aerosols, or propane. I'm looking at gas because I think it might offer a bigger bang and make the reloading of the fuel faster.

The only question I have is if the chamber would explode due to the gas explosion.

I say it would be faster because if it does prove to be theoretically safe I have designed a sliding mechanism. A hole in the side of the chamber and next to it a sliding cover that when the gun is in firing mode the chamber is sealed by sliding a piece of PVC over the hole either from inside the chamber or on the outside and when its ready to reload you pull it back and you fill it up. So its basically in essence similar to a bolt-action on a rifle.

What do you guys think? I'd rather blow my hand off, or worse so all input is appreciated.

tigeraceray wrote:I'd rather blow my hand off, or worse so all input is appreciated.

Excellent

The issue with gasoline is adequately metering and vaporising the correct amount of fuel.

Gasoline has a narrow combustion band much like Propane, so metering is difficult for maximum power. When too rich, the power is very low and makes lots of soot. When too lean, it won't ignite.

Haha I meant to say not blow my hand off. Mental lapse.

Thanks for the input. I'm going to do some tests with one of my old cannons.

What if the gas was placed in something like a ziplock bag? Could be useful for waking the neighbors haha

Edited by jrrdw.

tigeraceray wrote:What if the gas was placed in something like a ziplock bag? Could be useful for waking the neighbors haha

thats agianst the rules of the forum, and a bad idea it most likely brake in you barrel and throw petrol all over your yard

Not really a bad idea. Have you seen a bullet? There's the lead tip, and behind it is the charge. Which is confined in a casing, as would the gas be in my theory.

And the thing about the neighbors was a joke, don't take everything so seriously.

And of course I wouldnt be stupid enough to test it in my hand. Light a fuse in a old cannon and get back. If it doesn't work then obviously im not going forward with it.

Another way you can think about the idea is Caseless Ammunition. Those who play Black Ops have seen this.

Gasoline has virtually identical energy to propane, so there is no advantage there.

Gasoline is extremely difficult to measure in small quantities and to do an adequate job you will need a meter. A very small volume syringe, probably a syringe with a total volume of less than 1ml, will be needed. (Basically figure that gaseous fuels like propane have a density in the vicinity of 1g/L at STP but a liquid has a density around 1000g/L. So for a liquid fuel the fuel volume is decreased by a factor of 1000 for a particular chamber compared to propane.)

Overall, gasoline is a pita as fuel. It has no advantages and lots of disadvantages.

If you are considering using a liquid fuel read http://www.inpharmix.com/jps/Liquid_Com ... fuels.html

Propane and/or MAPP gas as been proven over and over again to be the optimal fuel for combustion spudding. Ease of use, cheap, safety, energy level..all reasons to lay down the hairspray.

A handful of gasoline cannons have been shown on the forum...don't waste your time.

Propane isn't really cheap. Just to do it I've seen most go for 100 to just get the meter and the parts. Out of the price range.

I don't know, I might switch to something else. Gasoline came to mind only because I haven't heard of any that used it. Figured it was worth looking at.

tigeraceray wrote:Propane isn't really cheap. Just to do it I've seen most go for 100 to just get the meter and the parts. Out of the price range

Youcando it cheaply

Butane + meter is less than $5. With a bit'o luck it can be done for $2.

http://www.spudfiles.com/forums/syringe ... 22301.html
Or, replace the butane lighter refill with a $0.99 disposable lighter
http://www.inpharmix.com/jps/Fuel%20Met ... ghter.html

tigeraceray wrote:Propane isn't really cheap. Just to do it I've seen most go for 100 to just get the meter and the parts. Out of the price range.

I don't know, I might switch to something else. Gasoline came to mind only because I haven't heard of any that used it. Figured it was worth looking at.

Perhaps then you should find a hobby that comports better with your financial resources.

Propane IS cheap. You can get into a metering system...



for about $40 US. Welding/camping propane is about $3-5 a bottle after that. One bottle will offer a full season or more of spudding fun.

---------
Edit.. Oh yes, Jimmy's solution above using butane even cheaper.

Dude I didn't say I was poor. I don't see a point to paying for a professional system at this point or on a experimental build like this one. I don't even know if all the additions will work so pouring extra money into it on a cannon that is purely a testbed is pretty stupid to me. Maybe on the next one I make if this one proves successful, but not for me on this one. Too many unknowns for me.

You can use a spray bottle with a fine atomizing nozzle for gas, however, with small cannons you'll be way overfueling it.
If you experiment to find the proper mix, it will be fairly reliable. Much more so than a comparable spray 'n pray.

I used a spray bottle to fuel a monster combustion made from a 5 gallon air tank, and about 5 1/2 full sprays worked well.

However, just watch for potential leaks if you actually want to attach the system to the gun. You will need a chamber fan, also.

Hey guys, most all spudders start with a spray & pray as their 1st combustion. In this case he was asking about fuel. His 1st will probably be a S&P. There's absolutely nothing wrong with that, they are a hell of a lot of fun...