What low pressure regulator can I use?

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Wizard
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Sun Jul 08, 2012 9:35 pm

New member from Oklahoma posting after spending all day searching and reading.

I have been working on a new project for a friend who owns a T-shirt shop who wants a t-shirt launcher.

I have most of my design figured out after reading as much as possible on here with what is available to me and my budget. I will list the specs and if im just completely off my rocker let me know, my primary builds are custom AR15's and AR10's so this was new but fun for me.

I will be using 3" SCH 40 PVC for the barrel and chamber, 6" chamber and 14" barrel connected with a 1" Modded Orbit sprinkler valve triggered by a high flow Air blower. There will also be a 120 PSI blow off valve installed in the back of the chamber for safety if the regulator was to fail.

Now the original plan was to use a 20oz CO2 tank for the air source but I think it would be better for the the ability to get more shots from one tank and not have to worry about the CO2 freezing anything vital. So I am now going with a Ninja Aluminum N2 Paintball Tank - 48ci 3000psi because it has the ability to be adjusted down to 450 PSI with the built in regulator and shims.

The tank will be connected at the front end of the chamber at the bottom of a 2" SCH 40 PVC T fitting and 1/4" inline ball valve so I can turn the fill on to charge the chamber and turn it off when the chamber has reached the PSI level I want for that shot.

The problem I am having is finding a 2nd regulator to install inline with the tank to bring the PSI down to 120 or so. Or do I even need to reduce the PSI from the tank any further?

Also I am still trying to figure out the piston and QEV to determine if one of those would be better for this and if I can figure out how to implement it in place of the sprinkler valve.

Any help for this noob would be great.

Here is what I have drawn up for the cannon. Any suggestions on something I might have screwed up?
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Lockednloaded
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Sun Jul 08, 2012 10:00 pm

That's a nice, detailed plan you've made, and as drawn it will work. I don't know if you care about ergonomics or how big this thing is, but it can be much smaller and more comfortable if you use a 3/4" QEV and some metal parts. I made a pretty effective t-shirt/tennis ball gun that was only about 20" long without the tank attached and it may be similar to what you want to achieve.

Now if you're sticking with your plans, there's one small thing you might change. Be sure tap fittings through double layer PVC (where fittings overlap pipe) your blow-off valve is in a dangerous spot right now.

As for your regulator, there are a lot of cheap paintball regulators on eBay that will work for you, but specifically, I recommend a Palmers Female Stabilizer. Its fully adjustable and reliable
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MrCrowley
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Sun Jul 08, 2012 10:08 pm

I noticed you keep referring to "SCH40" PVC, this has me worried you're not sure how to correctly identify pressure rated PVC pipe. If so, this should help:
http://www.spudfiles.com/spud_wiki/inde ... sure_rated
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Sun Jul 08, 2012 10:16 pm

Lockednloaded wrote:That's a nice, detailed plan you've made, and as drawn it will work. I don't know if you care about ergonomics or how big this thing is, but it can be much smaller and more comfortable if you use a 3/4" QEV and some metal parts. I made a pretty effective t-shirt/tennis ball gun that was only about 20" long without the tank attached and it may be similar to what you want to achieve.

Now if you're sticking with your plans, there's one small thing you might change. Be sure tap fittings through double layer PVC (where fittings overlap pipe) your blow-off valve is in a dangerous spot right now.

As for your regulator, there are a lot of cheap paintball regulators on eBay that will work for you, but specifically, I recommend a Palmers Female Stabilizer. Its fully adjustable and reliable

Ok I dont understand the part of your quote I highlighted in red

And thanks I will look that reg up. Plus the size isnt that big an issue as he wanted something that would be easily seen from the back of the bleachers but still be one man carried. So I was going to put a nice padded rifle sling on it once its completed.

MrCrowley wrote:I noticed you keep referring to "SCH40" PVC, this has me worried you're not sure how to correctly identify pressure rated PVC pipe. If so, this should help:
http://www.spudfiles.com/spud_wiki/inde ... sure_rated
LOL I have actually read that twice to make sure I understand it and even made a trip to lowes to check some things before anything was bought and found pressure rated PVC pipe. Compared it to the Non pressure rated pipe so I understand it and how to read the ratings that are printed on the pipes. I will be making a trip to a pluming supply shop in town to buy the pipe I need as lowes only has 1.5" pressure rated PVC.
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Sun Jul 08, 2012 11:08 pm

Wizard wrote:
Lockednloaded wrote: Now if you're sticking with your plans, there's one small thing you might change. Be sure tap fittings through double layer PVC (where fittings overlap pipe) your blow-off valve is in a dangerous spot right now.

As for your regulator, there are a lot of cheap paintball regulators on eBay that will work for you, but specifically, I recommend a Palmers Female Stabilizer. Its fully adjustable and reliable

Ok I dont understand the part of your quote I highlighted in red
.
Basically, the threads on the blow-off valve need to have surface area to grip onto in order to withstand the air pressure trying to push it out. If you increase the contact area between the male and female threads, you get a much stronger connection, so we try to tap hole into as much material as possible. You generally doing this by going through a thicker part of the chamber, which in this case is in the side of your cap, not the thinner dome part. In addition, the blow-off valve is very vulnerable to getting broken off in it's current position
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Sun Jul 08, 2012 11:12 pm

Lockednloaded wrote:
Wizard wrote:
Lockednloaded wrote: Now if you're sticking with your plans, there's one small thing you might change. Be sure tap fittings through double layer PVC (where fittings overlap pipe) your blow-off valve is in a dangerous spot right now.

As for your regulator, there are a lot of cheap paintball regulators on eBay that will work for you, but specifically, I recommend a Palmers Female Stabilizer. Its fully adjustable and reliable

Ok I dont understand the part of your quote I highlighted in red
.
Basically, the threads on the blow-off valve need to have surface area to grip onto in order to withstand the air pressure trying to push it out. If you increase the contact area between the male and female threads, you get a much stronger connection, so we try to tap hole into as much material as possible. You generally doing this by going through a thicker part of the chamber, which in this case is in the side of your cap, not the thinner dome part. In addition, the blow-off valve is very vulnerable to getting broken off in it's current position
Ah now I get it, thank you. I will adjust the location to the side of the cap once I put it all together so I can pick a safe spot for it.
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MrCrowley
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Sun Jul 08, 2012 11:42 pm

Wizard wrote:LOL I have actually read that twice to make sure I understand it and even made a trip to lowes to check some things before anything was bought and found pressure rated PVC pipe. Compared it to the Non pressure rated pipe so I understand it and how to read the ratings that are printed on the pipes. I will be making a trip to a pluming supply shop in town to buy the pipe I need as lowes only has 1.5" pressure rated PVC.
New members who actually do research beforehand, brilliant! :D
Wizard
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Mon Jul 09, 2012 12:19 am

MrCrowley wrote: New members who actually do research beforehand, brilliant! :D
LOL yea quite the novel idea if I say so myself. But I really like the idea of the QEV because it seems as if I can get more launch power with less PSI. But I havent been able to find enough info yet to implement it into my current build plans as I still dont quite understand them.

I like to be well informed before I start anything that could injure or kill me.

And since I sell Exploding Rifle targets as a part of my Gun Shop and I build real guns for a part of my living it pays to be informed cause its cheaper than a visit to the ER. HAHA :idea:

But not to detract from my current thread if you want to see what I have blown up I can start another thread lol.
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Mon Jul 09, 2012 12:22 am

MrCrowley wrote:New members who actually do research beforehand, brilliant! :D
:shock:

'tis one of the harbingers of the apocalypse! Repent, repent for the end is nigh!
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Mon Jul 09, 2012 5:55 am

Might I suggest a 1/4" street elbow between the chamber and the blowoff as well? This will keep it from stabbing you and knocking on things.
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Mon Jul 09, 2012 2:08 pm

Well im heading into town to buy the PVC parts I need. Going to a paintball pro shop while im at it to figure out the thread size and pattern of the HPA tank and regulator so I can get the correct fitting for the cut off/fill valve.

Wish me luck haha
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Mon Jul 09, 2012 2:20 pm

Since you're using a paintball bottle, you might want to consider stronger construction for higher pressures, linked with a quick exhaust valve.

A 3/4" QEV can be purchased relatively cheaply from eBay. This has lower flow than a sprinkler valve, but very fast opening. You can use this in conjunction with a smaller higher pressure chamber to achieve required performance.

If you use a ninja paintball tank, you can adjust this to 450 psi without the need for an additional regulator, and this pressure coupled with a relatively tiny chamber and fast valve is more than enough to fire off a t-shirt. You will need stronger construction - PVC won't cut it at these pressures - but on the other hand, the launcher will be more compact.

GGDT will help with virtual modelling before you commit to build.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Mon Jul 09, 2012 5:33 pm

@JSR, that's what I was saying...

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Mon Jul 09, 2012 5:54 pm

use the ninja n2 tank and the High-Flow Regulators with Pressure Gauge

from this site
http://www.mcmaster.com/#air-compressor ... rs/=ic55bx
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Mon Jul 09, 2012 8:06 pm

sagthegreat wrote:use the ninja n2 tank and the High-Flow Regulators with Pressure Gauge

from this site
http://www.mcmaster.com/#air-compressor ... rs/=ic55bx
Make sure if you decide to use a low pressure regulator, that it is rated for 450+ PSI input pressure. You may have trouble finding one, but Palmer's Pursuit regulators can be found on ebay and are designed for ~1000 psi input from CO2 tanks.


I agree with the other members here, and encourage you to go with metal construction and use the high pressure from the tank regulator through a QEV. You can fit much more air through a 3/4" pipe at 450 psi than at 150psi.
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