Ideas/Plans/Questions For My First Pneumatic

[miskaman]

So I've built 2 combustions, but they were too simple and don't as far as a pneumatic, so I want to make a pneumatic.

First off, what would it cost to build a very simple pneumatic? By simple I mean like a sprinkler valve, 1 chamber, and barrel.

What kinda of pipe should I use? I know ABS or whatever is a no-no. What about PVC?

Also, I heard DWV fittings are a lethal idea, so what kind of fitting is pressure rated and where can I find them?

One more thing. What should I use for a glue to attach a pressure gauge to the chamber?

[meatballs]

First of all, do some research, the answers to all of these questions are in the forums, the spud wiki, even try google searches.

To build a simple pneumatic, with a sprinkler valve, is probably around thirty dollars, less if you have pvc cement and primer (which is essential, you must use primer) and less if you already have pipe and just need the valve, blowgun, and fittings.
I have used pvc in all of my pneumatic guns. abs pipe is fine as long as its pressure rated. the vast majority of abs pipe available at home depot/lowes/hardware stores is cellular core which is not pressure rated. it is only for drains and things like that. make sure the pipe has a pressure rating on it. it should say NSF-pw, and should have a psi rating.
be very careful about dwv fittings. they aren't safe. dwv fittings are cheaper than pressure rated fittings cause they use less plastic, are usually thinner than pressure fittings, and the sockets that the pipe slides into aren't as deep. it shouldn't be hard to find pressure rated fittings up to two inch diameter. make sure any fittings say NSF-pw. occasionally a fitting will also say NSF-dwv on it, but as long as it says NSF-pw its fine. naturally a pressure rated fitting is safe to use in a drain. you can find pressure rated fittings up through two inch diameter at a home depot or lowes or hardware store.
do some research, try searching for info, if there's anything you can't figure out then ask. when im designing something i like to look at the showcase section for ideas. then i take different ideas and combine them into something new.

[pretzelperson]

I constructed one recently and posted pictures on this forum.

I made mine without spending much money. Here is my parts list:

Size "E" medical oxygen tank on Ebay = $12 (I got a great deal on shipping)
1" brass ball valve = $13
Metal schraeder valve = $4
Steel pipe fittings = about 10 bucks
1.5" X 10' pvc barrel and fittings = about $5
pressure gage = $7

Total: about $50.

Less about $10 if you eliminate the pressure gage. The reducing fitting for the gage cost about $3 and the gage about $7.

I opted for the oxygen bottle because it will never fail in this application. It has an operating rating of 2000 psi and the pipe fittings and ball valve are at 500 PSI I think. I know everybody tells me pressure rated PVC is safe up to 100PSI and most successfully use PVC but using PVC in this application is a risk that you don't have to take as there are other good options. I know with 100% certainty that my chamber is not going to fail and hurt me or anybody else. The big down side is that it is heavy. My oxygen bottle is steel, but you can buy an aluminum one that costs more and is much lighter.

I used the 3" diameter chamber from my old pvc air cannon (I destroyed my PVC air cannon to make this cannon) as a barrel on my new all metal one. It is great and was "free". All I had to do was to cut the 3" cap off one end and screw the other end into my ball valve. I also have a 5'X1.5" dia barrel and a 5'X1" dia barrel

The suggestion has been to replace the ball valve with a sprinkler valve or even better, a piston valve. I am sure it would make the gun much better, but for me the ball valve is good enough. I opted for the ball valve because it is designed for this application unlike a sprinkler valve. The ball valve is much safer than a sprinkler valve.

I put a 10' barrel on this gun and it launches spuds into what seems like low earth orbit. The compressor I used to pressurize this spud gun will pump 140 psi. There is a significant power increase from 100 psi I was limited to wtih my PVC cannon when compared to the 140 psi I can use in this new cannon.

[jrrdw]

Pretzelperson and Meatballs, i apploude your efforts, job well done!!!

[Infernal Maveric]

I have never used PVC to make Pneumatics, but I am very comfortable with using copper as it can withstand 400+ PSI and won't shatter if you get it wrong and is more durable than PVC.

The simplest Pnue. using copper would be:

Chamber: 22mm Copper pipe
Barrel: 15mm Copper pipe
Valve: 15 mm Ball-Valve
Filling: Schrader Valve/Quick-Connect

Other parts needed:

22mm End-cap
22mm-15mm reducer
Solder
Blowtorch

Not sure what the racks up to, as i haven't needed to purchase any copper pipe for about a year now as I have plenty left over from previous
projects.

Now, I know that a Ball-Value Pnue is pretty crap when it comes to opening times and accuracy, but it is the simplest Pnue you can make. If you want to add a bit more bang for your buck, file out the inside of the reducer so the pipe goes through it, Replace the ball-valve for a 22mm T and 22mm 90` elbow and a blowgun and fittings. Make a piston (Search button) and that will finish your pneumatic.

As for adding a pressure gauge, if using PVC, using a Tap and Die set will let you remove the gauge for newer guns, rather than glueing it in, if using copper, then solder on the apropriate fitting to the pipe, and screw the gauge in place.

[mtronic]

I made mine out of a pvc chamber and 3/4 poly pipe. Works like a charm, if you live in Australia poly pipe is easy to get a hold of and makes upgrades simple as pi also you can strip you gun for transport too

[veginator]

it shouldn't be hard to find pressure rated fittings up to two inch diameter.

Then where would be a good place to find 3 inch fittings because I have had some trouble finding them.

[Redcoat]

so what kind of fitting is pressure rated and where can I find them?

One more thing. What should I use for a glue to attach a pressure gauge to the chamber?

To answer your first question, They will be the fittings that have a pressure rating on them, also If your having trouble finding them just ask a store attendant where to find them. They also have things called Product Labels which should say Pressure Rated on them.

to answer your second question, Some sort of epoxy i would say, though I've never used the stuff.