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Simple Hybrid Cannon Idea

Posted: Sat Feb 24, 2007 9:28 pm
by From_Hamsterdam
Simple hybrid cannon idea
I found this out when i was trying to shoot ammo with sparklers attached. I did not add any fuel and i glued the gun together months ago but still resulted in a large 'bang' and more recoil then usual.

You will need:
A pneumatic cannon
Sparklers Or some thing that will burn in an enclosed space for a short time
Fuel

How to
1. Stick sparkler in back of ammo. You can protect the inside on the barrel from the heat of the sparkler by cutting up a aluminum can then putting the rolled up metal inside barrel.
2. Spray your fuel in to chamber though ball valve
3. Close up chamber, and pressurize
4. Light sparkler, stick ammo in to barrel (if Breach loading light sparkler when ammo is already in barrel)
5. Quickly turn ball valve to avoid more barrel damage from sparkler.
Tips/safety:
Do not use lots of fuel
Do not use high pressures
IMPORTANT: Turning ball valve too slowly might lead to chamber exploding :shock:

Would it be safe to try to repeat this? if so how much fuel and pressure should be used?

p.s I take no responsibility if you explode trying to do this. Sorry far any grammar or spelling mistakes.

Posted: Sat Feb 24, 2007 10:39 pm
by frankrede
very dangerous, thats called a bybrid,very dangerous.

Posted: Sun Feb 25, 2007 1:08 am
by willarddaniels
IMPORTANT: Turning ball valve too slowly might lead to chamber exploding
Um... at least you are thinking about being cautious... but there are more dangers present.
1. Most pneumatics are made from PVC and are not a recommended building material for hybrids. The material is too weak to contain a pressurized combustion. This combination usually results in damage to property (the gun and anything within range of shrapnel) and persons (anyone nearby).
2. Why risk damaging the barrel with the heat from the sparkler, thus making it weaker. See point #1.
3. Your combustion starts in the barrel and travels toward the chamber... There is a reason the barrel can be used with (somewhat) weaker material: There typically isn't as much force. ie. Sch 80 chamber and sch 40 barrel. See point #1.
4. Not a real danger, but an efficiency point. The projectile is well on it's way by the time the combustion occurs, thus wasting the boost.
5. Sparklers are cool because they are hot, emit sparks and last for a good length of time. Everyone like fire... except for things that your projectile may be hitting and causing to catch fire. Think about it: You are propelling a long-burning FIREwork very far away from your person. If it causes a fire, how long will it take you to get there? If you are aiming at a close target and your spud/projectile explodes or bounces away upon impact, thus flinging your sparkler somewhere... where does it go?

Posted: Sun Feb 25, 2007 2:16 am
by frankrede
Williardsdaniel you are now my favorite person in this forum with under 100 posts.
He obviously knows what he is talking about and welcome to the forum

Posted: Sun Feb 25, 2007 10:12 am
by BC Pneumatics
Willard, most hybrids are PVC. In fact, (one of?) the first was sch 40- and is still working fine :) )

Also, you one pointed out the federal laws this violates in most countries, or the multiple rule violations.

Posted: Sun Feb 25, 2007 10:28 am
by willarddaniels
I hear ya.
Sch40 pvc may be used for some hybrids, but I would never personally use it. Reasons: I usually over-build everything and err on the far side side of safety; I think that building more "serious" hybrids mean that you are using at least 4x.
I didn't even think about the sparkler flying through the air being a violation of most countries' federal laws; but then again, most laws are supposedly designed by those with good common sense to protect those who do not possess such capabilities. (although not always the case)

Posted: Sun Feb 25, 2007 10:57 am
by BC Pneumatics
I agree with you fully, I use sch80 for all of my hybrid chambers.

I think most laws are designed to combat Darwinism in modern society. If you are dumb enough to cut your fingers off with a chop saw, I say good riddance- no need for a (albeit funny) animation telling you not to.

Posted: Sun Mar 04, 2007 4:30 pm
by LGM
What about making a burst disk mortar like mentioned in other threads, filling it with fuel, and letting the sparkler pop the disk?
Now I want to try that.

Posted: Sun Mar 04, 2007 4:52 pm
by BC Pneumatics
1) You will damage the pipe with the sparkler
2) better performance from sparking at the back of the chamber and letting the flame front/ pressure wave burst the disk.

Posted: Sun Mar 04, 2007 4:52 pm
by willarddaniels
It would function, and even better than a breech-loader, except for the really tight seal; however, you still have the problem of a long-burning firework traveling very far away from yourself.
Do not ignore the most important danger with this idea: Your projectile is on FIRE!!!

Posted: Tue Mar 20, 2007 9:18 pm
by deusXmachina
<british> This week on Bad Idea Theatre....Violating firearms laws and picking chamber chunks out of skin, followed by a segment on brushfire</british>

Yeah while it sounds like a good idea on paper, there are SO many reasons why this can and will backfire in your face. Burst disks are clean, easy, simple, and SAFE.

And now for something completely different....

Posted: Wed Mar 21, 2007 8:48 am
by BC Pneumatics
Thanks machine god, got a good laugh outta that one :)
I must say though, it sounds like a very poor idea, even on paper.

Posted: Wed Mar 21, 2007 9:56 am
by joannaardway
It sounds like quite an interesting way to achieve hybrid operation.

A variant might be worth thinking about for a future design.