CO2 paintball claymore

[Humancarpentry]

I definitely agree with Jack. I would never try to fill a device rated at less than 1000psi with a remote line from your CO2 tank or HPA paintball tank as you can easily spike the pressure over what you intend very rapidly and blow the crap out of yourself. I decided to go with the 12gram CO2 option as it is very portable and easy to use, and the small amount of CO2 in each one limits the danger and destructive potential of the system. As soon as I get a chance to video my mine with paintballs in it, I'll post the results.

The total cost for me to build one mine, (not counting the tire fill 12 gram adapter) was about $25 in PVC parts, the sprinkler valve with modification, the shraeder valve, and the brass 1/2" to 1/8" NPT reducing bushing. I didn't count tool cost or epoxy cost, or PVC cement in this, as I had that stuff lying around and it is used to do other things.

I am interested in using this valve here:
to build a more compact version of the mine.

Does anyone (especially Jack) know what kind of pressure this thing can take? Also, to pilot this valve, could I just attach a blowgun trigger like I do with the sprinkler valve?

[jackssmirkingrevenge]

Does anyone (especially Jack) know what kind of pressure this thing can take?

Quite a lot, some folks on the forum have used them past 500 psi. The alloy body is unlikely to fail though you might see increased wear of the piston/diaphragm using higher pressures.

Also, to pilot this valve, could I just attach a blowgun trigger like I do with the sprinkler valve?

Yup. The umbrella type piston means these things can be piloted by a schrader valve.

[Humancarpentry]

So... you're saying that I built that claymore mine with a stupidly large (but still cool) sprinkler valve when I could have used a much smaller and easier to incorporate QEV for only about $10???

Why didn't anyone stop me?

Oh, wait... because I didn't actually post my plans for it before building it. I'll post updates of my mine when I get some time off work.

[jackssmirkingrevenge]

Why didn't anyone stop me?

Who are we, your mother?

[pigeon]

humancarpentry....I havent got started yet. Parts here in NZ are less easy to get. The sprinkler valves are well overpriced. Also I'd like to use a smaller valve as I want my mine to be as small and cheap as possible.

I dont know how those QEVs and pilot valve setups work yet......I guess I need to read more. If you posted your idea/design/shopping list, I'd be very much obliged

I havent started yet.....just been way to buy with tiresome real life stuff!

[Humancarpentry]

OK. Finally had enough free time to get this thing tested. Pics and Video to follow. Here is what I learned:

1. The overall design works well for liquid paint, powder, or paintballs.

2. When firing paintballs, it is better to switch to a straight 2" coupling for the barrel as opposed to the 2x3" expanding coupler. This is due to the fact that about 15% of the paintballs around the edge of the funnel shaped barrel will not be accelerated when the mine fires enough to reach breaking velocity. Switching to the straight coupling as a barrel fixes this and only decreases your payload by about 20%. It will still hold about 20 paintballs, which is more than enough. The funnel shape 2"x3" barrel still works fine for liquid paint and powder.

3. One 12 gram CO2 charge for this has plenty of power to break paintballs on a target at up to 15 feet distance from the mine. I didn't test it past that range, but I would not imagine that a trip-wire mine would need more than a 15 foot range.

4. It is critical to stake this thing into the ground, otherwise the trip wire will pull it off target and firing will cause it to swivel.

5. The paintball load is helped by placing a small crumpled newspaper wadding at the base of the funnel to better allow acceleration of the payload.

6. A paintball load has better range, easier loading and way less hassle and mess than a liquid paint load.

[Humancarpentry]

Pics... Loading and two test fires.

[Humancarpentry]

Here's a video. Sorry it sucks. My phone doesn't have a wide enough angle to capture the spread...

[jackssmirkingrevenge]

[youtube][/youtube]

We are throwing a party in honor of your tremendous success

It is critical to stake this thing into the ground, otherwise the trip wire will pull it off target and firing will cause it to swivel.

Can I suggest switching the blowgun for a ball valve?

[Humancarpentry]

Well, yes, you may suggest that... I have tried a few different ball valves but the real problem is that all of the valves I have found all seem to have rather high friction to move the lever, which actually worsens the problem.

I have modified the blowgun trigger to improve it with a simple fix already. I just haven't had time to take a pic and post it. Basically, all I did was wrap a rubber band a couple times around the trigger to provide compression and then tie the tripwire to a small spacer placed between the trigger and blowgun body. It now requires minimal force on the tripwire to pop out the spacer and the rubber elastic band pulls the trigger rapidly.

I'll post that in another month or so when I get more free time. Also, I am making the more compact MK-II version with a QEV valve as soon as I get around to that.

As far as parts go, I just used the common Orbit watermaster jar-top valve that is super cheap here ($9) and the standard mod. I used schedule 80 1" irrigation pipe nipples to connect, and then some 2" schedule 40 PVC with a 2"x2"x1" T piece (threaded on the 1" side, smooth on the 2" sides, with associated caps as seen in the pics. I used brass fittings to get down to the 1/8" NPT to attach the schrader valve.

[pigeon]

Ive only just gotten back to this. This is great Thanks for sharing - its exactly what Ive had in mind. Mine will benefit from your RnD - so thanks! Mine will be electronically triggered - I need to do it that way so I can make about 12 of them, and network them. Fire them by PIR instead of a trip wire - it'll be much easier and quicker to set up. Or fire them from a remote wireless trigger.

Really glad to see how well it works in theory. I'll always be using balls of paint, rather than liquid - better effect on target, and easier to load etc.

[pigeon]

Its a thing of beauty humancarpentry

[Humancarpentry]

Thanks, Pigeon! I am now working on refinements for the MkII version.

Thanks to Jack's knowledge, I am making a lower profile version using a smaller, cheap, modded QEV as the valve. The barrel will still be the same, and the chamber likely as well, although it would be possible to make a smaller, metal chamber at higher PSI. However, as your chamber gets smaller, you will transfer a progressively smaller percentage of the CO2 in the 12 gram. So, my next model will likely incorporate a cheap metal 12 gram CO2 adapter permanently attached.

This is actually quicker and easier than carrying around a CO2 fill device as then anyone with a 12 gram and some paintballs in their pack can easily re-charge and re-load the mine.

[pigeon]

look forward to seeing that QEV version. Can they be electronically fired? I really want to do that rather than trip wire......I have recently aquired Arduino skills which I want to use on them.

[Humancarpentry]

I am sure you could rig up something to fire them via an arduino wireless controller with electronic solenoids. I have no idea how to do that part. Will post the QEV version after I obtain some more parts...