Air Cannon

I am working on building my own Air Cannon. I want to be able to fire multiple shots (of T-shirts), in a short period of time so recharging the cannon between shots needs to be done by either a CO2 tank like on a paintball gun or any other suggestions you might have. Does anyone know where any good Air Cannon designs are on the web? The ones I have found all need to be recharged between shots with either a bicycle pump or an air compressor. The idea is to be able to mount one of these on our old robot and create a promotional bot for high school football and basketball games to shoot our T-Shirts into the stands like they do at professional baseball games and other events. The simpler the solution the better. I am also working on designing a way to auto reload the cannon between shots. Thanks for the help!

pretty much cant beat co2. as long as there is liquid in your tank you get about 1100 psi. all you need is a fat needle valve like a garden nozzle .shown here. get all the brass fittings and PVC at home depot and take the tank adapter off a paint ball gun and there you go a potato gun. or t-shirt cannon. or mega super soaker depending on what size PVC you use. guarantied not to catch fire and provide you with hours of fun.

A CO2 fire extinguisher is a good choice for propellant delivery - it comes with a nice valve, and can deliver a lot of volume in a short period. Just replace the standard extinguisher cone with a tube of sufficient pressure rating - PVC reinforced with fiberglass tape is a good choice.

Just be careful and think of safety first.

Don

Is that unregulated CO2 going into a garden hose nozzle? Most garden hose nozels I’ve seen are absolute junk. I’m no expert, but that just doesn’t look safe to me. I wouldn’t trust a garden hose nozzle to that kind of pressure.

this is some oddball forged steel nozzle. it has silicon rings and seals witch dont become frozen and dont crack. you can get it home deopt in the garden section for about $10

make sure to reinforce the pvc barrel i have seen them explode

Team 306 (Corry Robotics) brought a T-shirt shooting robot to our Ramp Riot Competition last November. I would look them up. They did an awesome job.

mechanical force always takes the path of least resistance. in this case air pressure. will always escape the easiest way it can. so as long as you don’t have something jammed in the barrel so hard that it wont move, witch in the case of a potato or A T-SHIRT is practically impossible for the pressure to escape by breaking through the barrel. the pressure will escape by pushing the potato out of the way. so here is some safety advise, just for good measure use at least sch40, and don’t cram junk in the barrel. and defiantly don’t try to stick it into the ground and fire it and don’t fill the barrel with water and try to launch that. the recoil will easily fracture your ribcage. never launch a t-shirt directly at someone launch it in the air and let if fall on them. I’m sure you all remember how Maude Flanders died on the Simpson’s. other than that have fun dispensing t-shirts

Yes we did, although its not very rapid fire, we charge it with 2 standard KOP air compressors, and the tank is (pressure rated) PVC. All we used for a firing mechanism was a solenoid from a sprinkler system, and it seems to work well . we used the proper adhesive to attach the end caps onto our tank, and even though it all checks out safety-wise, I still don’t like to stand in the way of where the tank ends are “aimed”. Some kids tried to emulate our tank with wood glue and non-rated PVC and put a hole through our schools door with the PVC cap. :slight_smile:

XInventions has a great area on air cannons and combustion cannons. First look at their combustion TP launcher (yes, toilet paper), get the general idea, and then look at their air cannons.

http://www.xinventions.com/main/spud/home.htm

Cool project! :cool:

How much CFM does it require to shoot off a T-shirt? I don’t know the answer myself, but most CO2 paintball tanks don’t have a large volume of air, but do have a lot of pressure (HPA tanks will go upwards of 800psi coming out the regulator). Now, if you grabbed a scuba tank size CO2 tank, then that should be plenty =D.

The first thing that comes to mind is just an ordinary pneumatic potato cannon setup, except you have a large HPA tank (scuba tank) with a regulator attatched, then feeding it into the air-storage tank of the pneumatic cannon. This way it’ll recharge pretty quickly after you fire (and this is sort of how paintball guns work). Oh, last thing I’ll note, I wouldn’t use the setup I listed above with CO2 – CO2 gets real cold when it’s depressurized into a chamber, and PVC becomes brittle when cold.

Hope this helps.

This topic has been brought up before, just search a bit for it. We built an air cannon robot last year and so did Team 1147, they brought theirs to a Kings game if I remember correctly. Ours uses a 4" barrel and can launch just about anything. We run it off of two large tanks as shown in the picks and bring them up to 100 psi with a separate compressor. We then actuate the gun using a spike relay controlling a sprinkler valve solenoid. We usually get 6 or shots before we need to recharge the tanks.

This should be an easy solution. At the fire department for extrication drills we have to use air tools and run them off of the breathing tanks. So if you make a trip to a fire department supply center/store they should have what you need. You just need an air tanks and tool adapter. The tool adapter should include the regulator, and it will end up hooking up to standard air house couplings. After that you just need a trigger and barrel. Hope this helps, if you want more info please PM me.

There’s some discussion of CO2 cannons over at http://www.spudfiles.com/forums/viewtopic.php?t=308&

Whatever you do, make sure all components are rated for the potential pressures involved at a particular stage, which can be up to about 2,000 PSI with CO2. Do incorporate a quality regulator and an overpressure relief device in the charging chamber. I would suggest using steel or aluminum tube for the barrel and avoiding any PVC for safety reasons.