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Using a paintball bottle for charging pneumatic canons..

Posted: Wed Aug 10, 2011 5:57 pm
by hoarp001
Hi Everyone,

Been away from the spudgun scene for a while, I used to own UKSGC, a small forum for the UK spudgunners. Unfortunately had to let it go, as very low users, and no one wanted to put in to help keep the site going.

Anyway , the other day I decided to resurrect my big tennis ball gun. I also decided to make a nerf barrel, for full size nerfs (nearly 4inches in diameter). I have made the barrel, and today I turned up a new plug to go in the end of the four inch piston valve, so all is going well, and I recon il have it ready in the next few days, but my one question is charging it.

I used to charge it up off a mains powered air compressor, which I no longer have. I also want to use it in feilds and stuff, its not going to shoot nerfs that fast, it would be fun to play with it in a feild and fire it up in the air and stuff, so I dont want to be tethered to the mains.

My first though is paintball cylinders. After doing some research, they seem cheap and cheap to refill, which is perfect, however there is one thing about them that is making me a bit nervous.

The pressure that comes out of the regulator is 850psi!!!

The gun is rated to 16 bar, however im only happy to run it up to 10 bar (140psi) and my tennis ball shots were all on 8bar (100psi).

Im obviously dubious about connecting an air supply that is capable of doing 850psi into something that would go bang at those pressures, however a paintball cylinder flow is quite slow compared to whats needed to fill the air canon up, so im thinking even though its very high pressure, the flow is so slow that i will be able to shut the cylinder off at 40 psi or whatever pressure i want, long before the pressure gets that high. Its still a concern though.

What does everyone think, has anyone powered an air cannon off a paintball cylinder before?

Posted: Wed Aug 10, 2011 6:08 pm
by Lockednloaded
Well there are lots of low pressure regulators you can choose from, but if you're going to cheap out, get an extremely low flow valve for filling and a pressure relief valve for you chamber

Posted: Wed Aug 10, 2011 8:15 pm
by Gippeto
I advise NOT F'ing around...do it right...or don't do it. No middle ground where your life and limb are concerned.

Palmers pursuit female stabilizer with a low pressure kit is EXACTLY what you need.

http://palmer-pursuit.com/cart/index.ph ... 2ic2s53fl0

Add a hose and valve of appropriate rating and you're set...and safe. :)

Posted: Wed Aug 10, 2011 8:21 pm
by Gun Freak
I agree with gippeto. Small errors can be very dangerous when dealing with co2.

Posted: Thu Aug 11, 2011 1:34 pm
by hoarp001
Hi Everyone,

Thanks for the response, that reg looks perfect.

We have however done some maths and worked out that the paintball cylinder would only fill the gun to pressure a few times. Im now looking at welding cylinders with a 10bar regulator on it, which is the cheaper option anyway...

Il let you know how I get on....

Posted: Thu Aug 11, 2011 2:03 pm
by hoarp001
Image

Image

Piston valve is ready.

Posted: Thu Aug 11, 2011 3:02 pm
by al-xg
How would you fill the welding cylinder though ?

They generally use diving tanks to fill paintball bottles anyway, too much of a hassle to fill them all individually.

Posted: Thu Aug 11, 2011 4:33 pm
by Technician1002
If you go the welding supply route, the cheaper options are beverage CO2 or Nitrogen. Both are relatively inexpensive compared to exotic welding gasses such as Argon.

For safety, a pop off safety valve is recommended. My two QDV cannons both have safety devices built in. The Marshmallow cannon is using the original pressure relief valve with the spring modified for a lower pressure (due to the bottle modification) and the larger cannon has retained the original burst disk.

My primary safety is the much lower pop off valve on my compressor. It opens at just over 100PSI.

Posted: Thu Aug 11, 2011 4:54 pm
by Hotwired
Hello again :)

I'm a UK deserter but honestly I don't make much of an appearance here anymore. Mostly lurk.

Lost interest mostly because I can't fire cannons round here much.

I'm currently about due to motivation to write up guides on making jellybabies (remember the code :D) out of disposable cameras. Proper ones mind you.

Good luck with the regulation.

Posted: Thu Aug 11, 2011 5:22 pm
by hoarp001
Ahh, this is nice, all the old UKSGC regulars are still about. Gonna get the welding cylinders full from the gas suppliers and then just get it refilled, im not gonna sit there and pump it up myself.

I was thinking regarding jellybabies, you know those electric fly swats that zap the flys? They give a pretty big spark, and they are 5 quid from maplin. Might be a good source of a cheap jellybaby....

Posted: Thu Aug 11, 2011 5:34 pm
by Hotwired
As a first stage of a jellybaby yes but not on its own.

It has a oscillator to bump up battery power to a few hundred volts then two voltage doublers after that. Output is a few thousand volts at most, jump maybe 1mm.

However if you use that few thousand volts to charge a capacitor in series with a spark gap and a high voltage coil with then you're in business and you'll be looking at tens of thousands of volts no problem.

Posted: Thu Aug 11, 2011 10:29 pm
by Judge_Jon
Absolutely viable option. Paintball guns are just mini spud cannons, I'm sure with a little research it would be nothing to get one working.

Posted: Fri Aug 12, 2011 12:36 am
by jackssmirkingrevenge
Hotwired wrote:As a first stage of a jellybaby yes but not on its own.
Ah, so mine wasn't broken :roll:

Pete, consider Ninja paintball tanks, great value for money and they have shim-adjustable regulators that will make them more manageable.