first constant air/sprinkler cannon.

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
ajnin
Private
Private
Posts: 3
Joined: Wed Aug 22, 2007 12:28 am

Wed Aug 22, 2007 1:16 am

Ok I have most likely 90% of the parts I need. Hopefully you guys can help me with the other 10%.

The tank is said to be adjustable 0-1200 psi, i will most likely use a palmers stabilizer which will act as a safety. is this needed?

am i going to be better off using compressed air or co2? availability of either is not a problem.

i would sorta like to keep the valve electronic, i have read that converting it to using a blowgun will increase power. i plan on using this for scenario paintball shooting either sabot style rounds or nerf vortex's. is the "power" difference going to be that big of a deal?

anyone ever used battery packs from rc cars for power?

last thing before the pics, is there a 150 ish psi burst disc? that would make me feel much safer, the sprinkler valve sits right next to my head.

http://www.fatalpaint.com/images/ajnin/cannon1.jpg
http://www.fatalpaint.com/images/ajnin/cannon2.jpg
http://www.fatalpaint.com/images/ajnin/cannon3.jpg

i hope i am atleast going in the right direction.
User avatar
frankrede
Sergeant Major 2
Sergeant Major 2
Posts: 3220
Joined: Thu Jul 20, 2006 9:47 pm
Has thanked: 1 time
Been thanked: 1 time

Wed Aug 22, 2007 1:24 am

You need a bigger chamber, with your current setup, I wouldn't expect the ammo to leave the barrel.
Current project: Afghanistan deployment
User avatar
f.c
Specialist 3
Specialist 3
Posts: 340
Joined: Sun Jul 08, 2007 2:40 am

Wed Aug 22, 2007 5:05 am

mate you need a much larger chamber. but other wise nice so far.
User avatar
chaos
Sergeant 3
Sergeant 3
Posts: 1205
Joined: Wed Jan 17, 2007 8:31 am

Wed Aug 22, 2007 5:11 am

i reckon he should just use a smaller diameter barrel, like for marbles, darts and stuff like that
User avatar
Redcoat
Corporal 4
Corporal 4
Posts: 835
Joined: Tue Feb 13, 2007 1:07 am
Location: Sydney ,Australia
Contact:

Wed Aug 22, 2007 5:33 am

i agree with chaos use a smaller barrel and shoot marbles or lead sinkers.
Poo.
to_live
Private 4
Private 4
Posts: 88
Joined: Wed Oct 25, 2006 3:55 am

Wed Aug 22, 2007 6:26 am

i plan on using this for scenario paintball shooting
thats all[/quote]
User avatar
homedepotpro
Specialist 4
Specialist 4
Posts: 443
Joined: Sun Nov 26, 2006 1:00 am

Wed Aug 22, 2007 10:34 am

what about the cell core abs he's using, does anyone else see a problem with that
Image
Intel Xeon
Private 4
Private 4
Posts: 84
Joined: Sat Mar 17, 2007 9:43 pm
Location: Philly, PA. (home's in Worcester,MA)

Wed Aug 22, 2007 10:55 am

It's a barrel. It's exposed to pressure for mere milliseconds. Plus, pressure rated pvc would be a pain to lug around
User avatar
VH_man
Staff Sergeant 4
Staff Sergeant 4
Posts: 1827
Joined: Sat Dec 09, 2006 6:00 pm
Location: New Hampshire
Been thanked: 1 time

Wed Aug 22, 2007 11:02 am

that regulator should work fine. i am getting one for the main regyulator on the 9mm airsoft rifle.

and yes, make the camber have at least the same volume as the barrel.........
User avatar
BigJon
Specialist
Specialist
Posts: 120
Joined: Wed May 30, 2007 12:21 pm

Wed Aug 22, 2007 11:11 am

I think you should build a chamber for it because with that big of a barrel I don't think that you'll get much power out of it. And as far as a 150 psi burst disc goes I would just put a pop-off valve on it. But keep the C02 for portability.
User avatar
homedepotpro
Specialist 4
Specialist 4
Posts: 443
Joined: Sun Nov 26, 2006 1:00 am

Wed Aug 22, 2007 12:35 pm

sorry assumed that was the chamber for some reason
Image
User avatar
PinHead
Private 4
Private 4
Posts: 75
Joined: Sat Jul 28, 2007 8:23 pm

Wed Aug 22, 2007 5:16 pm

The way that it looks to me, you don't even have a chamber, really, other than the fittings that go straight from your HPA tank to the sprinkler valve.

You should have a chamber that is just about as big as your barrel; you're going in the right direction tho. Theoretically you could shoot it the way it is, but in order to make it shoot anywhere you'd have to have your regulator cranked waaaaaaaaaaaaaaay up. Think about it - a typical paintball gun uses several hundred PSI to shoot something less than an inch in size, because it uses a low volume of air at high pressure. How much pressure do you think it would take to shoot something as big in caliber as a nerf football? Problem is, you can't even crank it that high anyways, cause your sprinkler valve won't take it.

The solution that almost all pneumatic guns on here use is to go with a larger volume of air to make up for the lack of pressure that you're limited to. I'd say shoot for a chamber volume that's about 80-100% of your barrel volume. From what I've seen on other guns of this style, you shouldn't need to go over 100 PSI (probably less) in order to get your desired speed. On the field, your gun will be limited by the chrono anyways.

Like I said, you're on the right track; just go ahead and add your chamber, and plumb your REGULATED air (good choice on the Palmer's reg, they're the best) straight into it. Then have your sprinkler valve coming out of that.
User avatar
DYI
First Sergeant 5
First Sergeant 5
Antigua & Barbuda
Posts: 2862
Joined: Sat Jul 07, 2007 8:18 pm
Location: Here and there

Wed Aug 22, 2007 5:51 pm

First off, I'd like to point out that that is one really strange tee you have there.

I'd also like to join the group of people who are saying something along the lines of "WTF dude. Where's your chamber?"

For the low pressures that that sprinkler valve can handle, you need a chamber at least 25% of the barrel size. With a larger chamber, say, 100-200% the size of the barrel, you could achieve a larger range of performance, depending on the pressure that you use.
User avatar
MisterSteve124
Corporal 3
Corporal 3
Posts: 702
Joined: Sat Feb 11, 2006 10:11 pm
Location: West Chester, PA
Contact:

Wed Aug 22, 2007 5:58 pm

You also need to put some teflon tape on those fittings, I'm assuming that you haven't because I don't see any.
User avatar
DYI
First Sergeant 5
First Sergeant 5
Antigua & Barbuda
Posts: 2862
Joined: Sat Jul 07, 2007 8:18 pm
Location: Here and there

Wed Aug 22, 2007 6:00 pm

I don't think that it's really built yet, just put together to show us what it looks like. He may also be using some form of pipe dope which is difficult to see.
Post Reply