SpudFiles

Hey guys, I have been spudding for a while now. I currently use AquaNet hairspray for fuel. It produces excellent power, but no visible muzzle flash unless it's at night.

I am looking for a fuel that produces a nice, visible muzzle flash, and provides the same amount, if not better, power as the AquaNet.

Please help me out, I am willing to spend as much money as needed.

http://www.spudfiles.com/spud_wiki/inde ... n_Spudguns

Take your pick. Most people use propane, its cheap and effective.

A big flash usually means you had unburnt fuel in the barrel, which is inefficient in terms of power.

This is a properly metered fuel mixture (approx 4% concentration by volume) in a clear tube firing a tennis ball at 1000 frames per second:

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This is an excess of fuel (approx 7% concentration by volume):

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The second one has a bigger flash, but clearly the projectile accelerates less.

Correct fuel metering is crucial, plenty of ways to do it but a syringe is one of the simplest:

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Thanks for taking the time to put all of this together. I can indeed see why a bigger flash would mean more unburnt fuel.

Anyway, I have never used propane before, and I also don't know the volume of the chamber when the cannon is loaded.

How would I go about adapting my cannon for propane use? In other words, what supplies would I need?

Some pics and dimensions of your cannon will help us help you

I will get on that now.

In the meantime, check out the flash from properly metered butane (gas lighter fuel) with a syringe, in daylight

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Here she is completely assembled.


Here is my ignition system. A grill igniter that sparks extremely fast.


This is the inside of the chamber, with the 2 ignition screws together.


Here it is disassembled.

The combustion chamber is 3 inches wide and 12 inches long. The barrel is 1.5 inches wide and 18.5 inches long.

If you need any more measurements, let me know.

Let me fix the images, not sure why they aren't showing...

They are fixed now.

Squerl101 wrote:If you need any more measurements, let me know.

Your chamber volume is approximately 85 cubic inches, so you would need around 3.5 cubic inches of propane, around 60cc.

All you need is one ofthese, some tubing and a source of propane or butane - no need to make any modifications to the launcher.

Just stand the launcher muzzle down, open the back, squirt the propane in slowly from the syringe as you would have done with the aquanet, close and you're good to go.

Edit: As you barrel is removable, you can also fuel directly into the chamber with the barrel removed, this is the option I would choose.

Make sure you vent the chamber properly between shots.

Thanks, I have just ordered one.

So I would fill this up completely with propane, then inject it, then close it right away, and then it is ready to fire?

Pretty much.

Jimmy has a nice tutorial on how you can use a disposable lighter as a fuel source: http://www.inpharmix.com/jps/Fuel%20Met ... ghter.html

Ok. Also another question, I have seen people just mount their tanks on their cannons. They also have a gauge. How do they measure propane in a situation like that? If easy, I would like to use that instead of a syringe.

read up: http://www.burntlatke.com/lp.html

I'll read everything. It looks like a very useful site.