My First Pressure gun ever. Over/Under Design, need help.

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.
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Ragnarok
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Sat Oct 30, 2010 2:29 pm

Yukondano2 wrote:Is it really necessary to put Teflon tape on the valve?
Definitely recommended.
Because if i ever make another one i might want to be able to remove the blowgun to put it on other valves.
... Teflon is a lubricant, it's not some kind of glue that will make it impossible to disassemble the joint later.
Does that thing kinda look like a big cat to you?
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Gun Freak
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Sat Oct 30, 2010 2:29 pm

13 bucks is pricey? Thats cheap, for such a good valve. But, you can build a higher performance piston valve for cheaper, if you have the knowledge and skill.
Is it really necessary to put Teflon tape on the valve? Because if i ever make another one i might want to be able to remove the blowgun to put it on other valves.
Teflon tape is not an adhesive, so sticky properties. Don't let the word "tape" fool you. It just wraps around the threads to seal it. Blowguns are only 7 bucks, and taking it out only weakens the threads, so I'd just get a new one if you need it for another project.
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Yukondano2
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Sat Oct 30, 2010 2:49 pm

Ragnarok wrote:
Yukondano2 wrote:Is it really necessary to put Teflon tape on the valve?
Definitely recommended.
Because if i ever make another one i might want to be able to remove the blowgun to put it on other valves.
... Teflon is a lubricant, it's not some kind of glue that will make it impossible to disassemble the joint later.
Woops. Sorry i failed XD
Good to know though. However if these things are around 13 bucks and blowguns 7, i'm looking at more than 20 dollars for this since i got the 1/8" nipple and the 1/4" to 1/8" piece. I looked into how it works though. It releases air, changing the pressure in the sprinkler so that the diaphram lifts up and fires. Seems very simple then. The fact i have to mod it is irritating but, ho well.
-EDIT-
Read what i get when he mods it. No blowgun. Really that kinda Sucks, I'm guessing it'll be cheaper if i do it myself.
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Gun Freak
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Sat Oct 30, 2010 2:57 pm

Put a female quick connect fitting on your blowgun and a male quick connect fitting on each gun you need the blowgun on then you can switch between each one quickly.
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Yukondano2
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Sat Oct 30, 2010 3:56 pm

Gun Freak wrote:Put a female quick connect fitting on your blowgun and a male quick connect fitting on each gun you need the blowgun on then you can switch between each one quickly.
Thanks! That'll save me some cash for later models. I definetly don't have enough cash to pull this off yet.. is there a way to remove PVC Primer + Cement so i can attach it to something else? Preferably that doesn't involve cutting it off and sticking em together with couplings?
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Sat Oct 30, 2010 7:45 pm

Yukondano2 wrote:Is there a way to remove PVC Primer + Cement so i can attach it to something else? Preferably that doesn't involve cutting it off and sticking em together with couplings?
Not really. There is a tool that can dig out the pipe in the socket of the fitting, but they are expensive and specific to one pipe diameter. The only other option is to sand or dremel or similar the pipe out from inside the fitting but that makes is rough and not really safe. Buying a new fitting is worth it. I'd imagine the bond between properly welded joints is as strong as the pipe itself, so melting it out isn't really an option either. So to answer your question, no.
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Yukondano2
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Sat Oct 30, 2010 9:11 pm

Yeah Gun freak i can understand that. I just hoped there was some kind of solvent.
So my new model hope to get made soon is pretty much the same, though I'm going to try to get the barrel to touch the compression chamber so i can tape it down for stability, and so it can be more compact. I'm switching to a One inch barrel, and I'm going to see if i can get a modded sprinkler valve for a trigger. Are there any other potential issues with a design like this?
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Gun Freak
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Sat Oct 30, 2010 9:13 pm

Just make sure you use all pressure rated parts and correctly and carefully mod the sprinkler valve. It should be pretty easy.
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Yukondano2
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Sun Oct 31, 2010 10:59 am

Gun Freak wrote:Just make sure you use all pressure rated parts and correctly and carefully mod the sprinkler valve. It should be pretty easy.
Not sure how to find that out. I know the pipes are, but i cant' find pressure ratings on the Couplings.
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Gun Freak
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Sun Oct 31, 2010 2:30 pm

It doesn't have an actual rating on fittings, they just need to say NSF-PW.
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Yukondano2
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Sun Oct 31, 2010 4:12 pm

Gun Freak wrote:It doesn't have an actual rating on fittings, they just need to say NSF-PW.
Right, good to know. Thanks for the help guys. Once i get some more parts and the modified sprinkler valve i should be good.
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Yukondano2
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Sun Oct 31, 2010 5:58 pm

Hey, about LaunchPotatoes.com
is it a trustworthy site? I really want to buy a modded sprinkler valve, seeing as how the person who does it is probably more experienced than me, but i don't want to order it and then have it not arrive. How does he ship and get the money?
-EDIT-
Never mind, I'm not going to use the site. Even if i have to pay extra money I really just don't want to buy from that site. I have NO idea if its any good.

Is it necessary to THREAD the hole you drill in a sprinkler valve when you put in the 1/8" Piece? I mean its not like I'm going to be removing it.
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Technician1002
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Sun Oct 31, 2010 6:46 pm

I recommend 1/4 inch instead of 1/8th inch. There is an excellent tutorial on modifying sprinkler valves.

http://www.spudfiles.com/forums/modding ... -t305.html

I do not have any first hand experience with Launch Potatoes as I build my own valves.
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Yukondano2
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Sun Oct 31, 2010 7:16 pm

Technician1002 wrote:I recommend 1/4 inch instead of 1/8th inch. There is an excellent tutorial on modifying sprinkler valves.

http://www.spudfiles.com/forums/modding ... -t305.html

I do not have any first hand experience with Launch Potatoes as I build my own valves.
Thanks for the new Tutorial. That should save me some money, though do i really need to use a hose?
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Gun Freak
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Sun Oct 31, 2010 7:38 pm

Don't use a hose, put the pilot right into it. Hose is more money and less performance. More air for the pilot valve to exhaust, slower valve.
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