Basic Nerf Cannon Help

[RabidDuck]

That's what I'm planning on doing. Using a PVC chamber instead of a soda bottle.

[millons70]

My brother is actually into modifying nerf guns to make them shoot farther. The whistle darts (the big soft rubber-ish head) fit perfectly inside 1/2.

I've found out that you need very little air to make these things shoot far, and it's easily possible to make the tank too big.
Make it with too much air and the dart spins out 5 feet in front of the barrel.

One of the most successful nerf dart shooting cannons I made was something along the lines of;

barrel- 2.5feet of 1/2
Valve- Half inch ball valve from Menards (they turn really quick) You can also mod a sprinkler valve, but there's really no need to waste the money on one.
Tank- 2.5feet of 1/2. Put and end cap with a tire valve through it, and voila!

I got around 300 feet using one of these with only a bike pump, which was probably only up to 70psi. Don't let that scare you, literally 5 pumps and the tank will be at 70psi, since the tank is so small.

[millons70]

If needed, I can post a picture of it, very simple and easy to make.
But if you want something awesome, you can increase the air tank size, and make a shotgun barrel.

A shotgun barrel attachment is easy to make.

Just cut about 4-6 lengths of 1/2 (depending on the size of pipe your're going to nestle these into)

Cut a 6 inch length of 3 inch, and neatly place as many barrels as possible into it.

Then stuff the open holes around the barrels with like packing peanuts (preferably foam backer rod, also known as caulk saver. They sell it at Home-Depot, only about $4) Use any sort of easily apply able adhesive (hot glue works great) to hold in the foam in the gaps. Then you can add a bell reducer to it (it's not going to be under pressure since it's on the barrel side, so it's safe to use)down to whatever valve size you use.

If your're going to want to use a different barrel, and want it interchangeable, use a male and female thread coupler.

I've made one of these to shoot homemade nerf darts (stephans) with 1/2 cpvc, and it works great!

[RabidDuck]

Thanks for the input and past experience. Had some time to talk with some other spud filers today and was told to go with a 2:1 chamber to barrel ratio. I went out and made my chambers tonight.

Barrel: 1/2 inch in diameter and 24 inch in length
Chamber: 1 inch in diameter and 48 in length.

Going off what you said that chamber may seem huge however I'm using JSR's idea of a slide valve and and making the cannon semi automatic. So the larger chamber allows for more shots.

I really really like your shot gun idea and may look into once I get the main piece done.

I did notice though that the PVC 1/2 inch was quite large compared to the 1/2 CPVC. The dart falls through the PVC and has lots of room while the in the CPVC it's a snug fit but can be pushed in. I used it as a dart gun and it worked very well just powered by my lungs. Is it okay to use the CPVC for my barrel even if it's not pressure rated?

I ordered my valves to a local store and paid an arm and a leg for it but that's okay because I want them quickly. I will be picking those up on Monday.

Here are some pics for right now:

End caps: http://cdn.imghack.se/images/98ee6a895c ... eb5bf5.jpg

Everything:
http://cdn.imghack.se/images/4d8ffa8697 ... a54b41.jpg

Quick Connects:
http://cdn.imghack.se/images/1ed17b6293 ... 80762c.jpg

Pressure Gauges:
http://cdn.imghack.se/images/c116eeb16f ... 2e7b35.jpg

Dart:
http://cdn.imghack.se/images/1992133db1 ... 30d327.jpg

PVC vs CPVC:
http://cdn.imghack.se/images/786fafb0f2 ... f4e925.jpg

PVC:
http://cdn.imghack.se/images/7ec99cf38a ... 8ead92.jpg

CPVC:
http://cdn.imghack.se/images/8ea55c9eb7 ... e4cb91.jpg

Thanks for all the help and input guys! More is welcome and hopeful!

[jrrdw]

2:1 with half inch barrel and one inch chamber....1/2"X24" barrel:1"X24" chamber = 2:1.

48"X1" makes it 4:1 because the chamber size is all ready twice the size of the barrel.

[RabidDuck]

I thought it was diameter and length you factored in? Must of mistaken what you told me! Oops.

Is this a horrible thing or will it just mean I have a lot more shots to use?

I can always cut it down and get a few more end caps.

[jrrdw]

That is diameter and length factored in. I was mistaken about the length....You can keep it 48", it just gives you more air.

[RabidDuck]

http://www.grainger.com/Grainger/LEGRIS ... Pid=search

http://www.grainger.com/Grainger/LEGRIS ... Pid=search

Thanks guys!

Could someone explain to me the fittings for all of these?

The QEV are all three female half inch correct? So i'll need male half inch adapters to connect the cannon?

For the slide valve it looks like one end is a male half inch and the other end looks just like a pipe?

How do I go about this?

Thanks much!

[jackssmirkingrevenge]

The QEV are all three female half inch correct? So i'll need male half inch adapters to connect the cannon?

For the slide valve it looks like one end is a male half inch and the other end looks just like a pipe?

Your chosen slide valve has two female connections, so you will need a 1/2" nipple to connect it to the QEV. On the other end of the slide valve, you need to connect your main air supply.

For the chamber side of the QEV, I would suggest a simple 1/2" plug for starters because you can probably get by with just the air in the QEV body. For the barrel side what I would do on a limited budget is epoxy a 1/2" nipple to the barrel and connect it that way.

[RabidDuck]

How will I connect the slide valve to the female quick connect on my main air supply?

Also for the barrel to QEV connection I was planning on using a replaceable barrel. So it'd be a 1/2 inch female to 1/2 inch male correct. Male end screws into QEV.

Does the barrel need to be pressure rated? Like I posted before that the CPVC fits better. Is this okay?

[jackssmirkingrevenge]

Pvc is perfect for a barrel.

As to connecting the slide valve, you can find male quick connects with male 1/2 threads, for example: http://www.ebay.com/itm/5Pc-Air-Tool-Ac ... 0948737287

[RabidDuck]

All i'm saying is the CPVC would be better but I don't believe it's pressure rated.

PVC vs CPVC:
http://cdn.imghack.se/images/786fafb0f2 ... f4e925.jpg

PVC:
http://cdn.imghack.se/images/7ec99cf38a ... 8ead92.jpg

CPVC:
http://cdn.imghack.se/images/8ea55c9eb7 ... e4cb91.jpg

See the difference?

[dewey-1]

What is the OD (outside diameter) of the CPVC barrel.
Normally CPVC is used for hot water applications.
Where did you buy the CPVC pipe? Is it 1/2 inch?
Are there any markings on the CPVC pipe?
Is this what you bought?
http://www.homedepot.com/p/t/100170202? ... =100170202

This will work for barrel to 1/2 NPT QEV.

http://www.homedepot.com/p/t/204186849? ... %2d%5f%2dN

Or this:
http://www.homedepot.com/p/NIBCO-1-2-in ... /100159268

Or this:
http://www.homedepot.com/p/KBI-1-2-in-C ... /204186929

[RabidDuck]

The outside diameter is 5/8 inch. I bought the CPVC at Menards Hardware Store. The tube says it's 1/2 inch. SDR-11. NSFPW. 100 PSI @ 180 degrees F. 400 PSI @ 73 degrees F.

[dewey-1]

All i'm saying is the CPVC would be better but I don't believe it's pressure rated.

Did you not just answer your own question?