ideas???????

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
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bigbob12345
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Thu Apr 03, 2008 2:41 pm

Here is where you can get a QEV
http://www.mcmaster.com/

scroll down, the one you want is model F

just put a blowgun or ball valve ion the pilot side, screw it in and its good to go
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WEEMAN
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Thu Apr 03, 2008 2:44 pm

give me some slack im dumb ok
whats it under....
add me to whatever instant messaging you use so i can communicate easier...
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bigbob12345
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Thu Apr 03, 2008 3:48 pm

search part #6646K23 and you should come up with the excact thing you want.
i dont really have an instant message account so if you want to communicate easier how bout we just go over to the chat which there is a link to at the top of the spudfiles home page.
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DYI
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Thu Apr 03, 2008 6:53 pm

You learn quickly in this hobby.

The QEV is your best option for a small, rifle sized launcher operating at reasonable bike pump pressures (<160 psi). And it took me a few months to find them on McMaster, as they aren't very intelligently placed in the catalog.

Unless you're using higher pressure than a bike pump can generate, or have lots of money to burn, you might want to consider simply using a steel chamber, or even PVC if a little danger doesn't bother you. Pressure rated PVC fittings will always have "NSF-PW" printed on them, and the pipe will list an actual pressure. All iron or steel fittings can survive a lot more than most people can fill them to.

You may also want to consider typing more legibly - it makes the forum look nicer and more proffesional, which helps greatly with a hobby like ours.
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Counterstriker
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Thu Apr 03, 2008 6:59 pm

When I first joined last year around same time.. I am made a topic like this and no one really gave me idea's, It was a good thing because I then created my own gun idea. Good luck.
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TurboSuper
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Thu Apr 03, 2008 7:59 pm

Ok, listen... you aren't designing the next space shuttle here.

A pneumatic consists of three things: A chamber, a valve, and a barrel.

Generally speaking, a larger chamber with a fixed barrel size will lead to an increase in power, although the higher you go, the smaller that increase becomes.

A good guideline for pneumatics is a 1:1 C:B ratio...go use GGDT if you wanna do sumpin' fancy.

With these simple guidelines, a pneumatic shouldn't be too hard to figure out...
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Counterstriker
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Thu Apr 03, 2008 8:23 pm

If you want the by far Easiest way to make an pneumatic here's how..

Go out to homedepot and buy this...

1.Pvc primer and cement
2. 2" precut pvc, Make sure its pressure rated. (usually the store has precut 2 feet of the stuff)
3. 1/2" pvc (You could use 3/4" maybe even 1" but 1/2" can shoot cooler things)
4. A 1/2" brass ball valve.
5. 2" to 1" bushing PRESSURE RATED
6. 1" to 1/2" bushing PRESSURE RATED
7. TWO 1/2" male threaded adapters
8. Shrader valve (Airvalve)
9. A 2" Endcap
10.Teflon tape

What your gonna want to do is start buy cutting 2 inches of 1/2" pvc, put that aside, Then drill a hole in the 2" pvc or cap for the shrader. Then screw that into place, then weld (When I say weld I mean Solvent weld, look it up..)the cap onto the 2" pipe. Next weld the 2" to 1" bushing to other side of the 2" pipe, then the 1" to 1/2" to that. then from that 1/2" bushing get that 2 inch piecs of 1/2" I told you to cut and weld it in there, then on the other side weld the 1/2" male threaded adapter, teflon tape the threads and start to screw on the ball valve, then from the 1/2" of extra pvc cut a barrel, 3 ft is good. On one of those weld the other male threaded adapter, Screw that into the ball valve (Teflon tape isn't neccesary becuase there is no high pressure on the side of the barrel.)

Let sit for 24 Hours and have fun!

Make sure it is all pressure rated.. Not DWV or you will get put under arrest by the DWV police.
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DYI
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Thu Apr 03, 2008 8:56 pm

It can be DWV, as long as it's pressure rated...

Bigbob actually had a decent generic design, but the above would be about as powerful as a blowgun, and a lot less safe.

Just go with a QEV and a steel/copper chamber.

I must be in a great mood today getting all that stuff from McMaster, because normally I'd be ranting about using the search function...
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Counterstriker
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Thu Apr 03, 2008 9:04 pm

DYI wrote:It can be DWV, as long as it's pressure rated...

Bigbob actually had a decent generic design, but the above would be about as powerful as a blowgun, and a lot less safe.

Just go with a QEV and a steel/copper chamber.

I must be in a great mood today getting all that stuff from McMaster, because normally I'd be ranting about using the search function...
It would be less safe, why? The reason I made that post is because I doubt he will want to go through all the trouble of modding a sprinkler valve (even though its a 1 minute job),
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DYI
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Thu Apr 03, 2008 9:29 pm

It would be less safe because PVC is not rated for use with compressed gas, and has extremely poor failure characteristics if it is used with compressed gases.

And you don't have to mod a QEV at all :wink:
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Fri Apr 04, 2008 12:32 am

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WEEMAN
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Fri Apr 04, 2008 3:00 pm

lol nobody luagh its an inside thing??>....
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SpudFarm
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Fri Apr 04, 2008 3:03 pm

that maked me rofl ;)
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Counterstriker
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Fri Apr 04, 2008 3:03 pm

DYI wrote:It would be less safe because PVC is not rated for use with compressed gas, and has extremely poor failure characteristics if it is used with compressed gases.

And you don't have to mod a QEV at all :wink:
Sprinkler valve, Isn't better if you mod it?.. A noob would screw it up, If it's his second gun he should go simple...
Last edited by Counterstriker on Fri Apr 04, 2008 3:09 pm, edited 1 time in total.
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bigbob12345
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Fri Apr 04, 2008 3:04 pm

:lol:
that is all i have to say
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