Judge Dredd

[geardog32]

this is my first air cannon everything is sched 40 pressure rated stuff. i need some suggestions for a color scheme maybe a pattern. i will post damage pics after i finish my fridge pump.

name: JUDGE DREDD

specs:
chamber: 3" x 30"
barrel: 1"x4' ,2"x4' and 2"x24"
valve: modded rainbird cp100 sprinkler valve
other: 300psi gauge quick disconnect fill




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[c11man]

very nice first gun. cant wait to see what you can make with a piston valve. now we need some damage.

a frigdy? what pressure do you plan on usin?

[DinerKid]

flat black. you can't go wrong with it.
nice looking cannon nice job especially for a first

[geardog32]

i wont be able to get damage pics or even test it until i finish my fridge pump because i have no other way to pressurize it. i dont plan on taking it any higher than 110-120 at the most. not quite sure of my next design but it will definitely be a piston valve. as for color i was thinking of flat black but i was hoping to do something a little more appealing.

[DinerKid]

try to paint it grey all over then use leaves as stencils and just mist it with black like a kinda camo look ya know?

[THUNDERLORD]

Very nice PVC pneumatic!
You could fill it with propane.
Or get a 10$ bike pump.
They burn out easily from spud use eventually.
The foot pump kind work the best IMO. Good luck on the fridge 'pressor
You'll probably want to breech-load it too. 8)
EDIT: forgot, I like your pilot configuration.

[geardog32]

i was thinking about getting a bike pump as like as like a back up but i dont have a schrader valve. is there a way to hook up a quick disconnect fitting to one?

[spudtyrrant]

i was thinking about getting a bike pump as like as like a back up but i dont have a schrader valve. is there a way to hook up a quick disconnect fitting to one?

cut the hose below the schrader attachment take it to the hardware store and find a hose barb that fits inside it and then atttach the threaded and to a quick connect

[geardog32]

thank you. one more thing that i did not even notice till now but, i see that most people who have gauges and fill valves seem to be in places where there are two layers of pvc like at a coupling. i was just wondering if this is going to be a problem on my gun, if so i can just get some air fittings and fill them with epoxy and then epoxy/screw them into the existing holes and drill two more holes in the coupling.

[Marffy]

nice sprinkler/pilot valve setup
flat black would look great
you might like a "bolt action" barrel
build a wooden brace between the air chamber and the barrel
It would be cool to see a mini 250psi compressor with 12v battery on there.
mini compressor would take forever tho

[Ragnarok]

@Marffy:

Point 1: The thread is four months old. Threads that old should only be posted in if you really need to and have something big to add.

Point 2:

It would be cool to see a mini 250psi compressor with 12v battery on there.

Don't get the idea the mini compressors are worth anything. They're slow, frequently don't get the claimed pressures, and tend to break very fast.

They are what they say - emergency compressors. Designed for use once in a blue moon (and even then, I'd rather have a foot pump in the car), not the constant use that spudding would demand of them, which is why almost any spudder who's ever spent money on them has regretted it.

[geardog32]

hmm... yeah little compressors are garbage and the gun looks i a little more like this now.

[tonnor]

Dear sir
I am looking at one of your air cannons on the site .Is it designed for tennis balls?I am building one and using 24 inch of 2.5 sdr21 for the barrel and dont know what size to make the 4 inch air chamber.Also i am using two inch from the air chamber to the valve would this make a difference i belive you used a smaller diameter.How much height are you getting? how much distance?I am building this for my sons school project and they are going for height and distance.Any help would be appreciated.Thanks

[jackssmirkingrevenge]

Dear sir

No need to be so formal

I am building one and using 24 inch of 2.5 sdr21 for the barrel and dont know what size to make the 4 inch air chamber.

Generally having the chamber roughly the same volume as the barrel is sufficient. If you're looking for performance though, maybe go overboard and double that to make sure you're wringing every last foot pound out of it and I would definitely try to use a longer barrel unless there are project size restrictions.

Also i am using two inch from the air chamber to the valve would this make a difference i belive you used a smaller diameter.

It doesn't really make a difference in this case if the valve is still 1"

edit: bleh, lol.

[Insomniac]

Generally having the chamber roughly the same volume as the chamber is sufficient.

Indeed, some would even go so far as to say that it is required.