[Vikingdad]

I can't believe that my boys and I are the only ones who have made compressed air cannons and fooled around with different configurations and such, so I figure I would start a thread on the subject.

Tonight I get home and the boys are working on a project we started a few weeks ago. The air tank is an old CO2 extiguisher, godd for 2000 PSI, we have added a gate valve, a fill valve and an adapter that we can thread on different barrels to. Currently it has an 1.25" schedule 80 PVC pipe for the barrel (all other pressurized fittings are brass or steel). The barrel is 10 feet long, which I think is too long and we are losing some velocity out of it but the boys refuse to cut it.

The projectile started out as a standard glow stick. It doesn't go too far by itself (out of a smaller bore) so we taped a broken arrow with the fletching on it to the back. That did OK, but only made it about 200 yards.

Tonight, they had made a wooden head out of a closet rod, it is about 3" long. In one end they drilled (on the lathe) a hole for the glow stick and the other end got a hole for an arrow shaft. This sucker went exactly 321 yards 9 as measured with a Leupold laser range finder).

We retrieved that and put the wood plug on the lathe and made it more of a teardrop shape for aerodynamics. First shot the thing came apart, but we found all of the pieces. We didn't get a second shot because mom called us in for dinner.

Oh, and all of this is being done in the dark. Its much easier to find the projectile when we use a glow stick in the dark rather than watching for it in the daytime and calling the boys into it from the house (we did this with tennis balls- lost a couple).

Here is a pic of the last configuration.

[dango]

Obamination regulations: Nor more than 2 lbs. psi. , must be kept to single shot,
projectile must be pink and 3mm. Dia. foam-rubber , retort must "Hail obama (Pfffffft. , color of mechanism must not be (BLACK) , compressor must be turned on when firing and off when loading (Single shot thingy) , all compressors shall be registered and none to be more than 30 lbs, psi. MAX!

Any changes made by personage owning said "Weaponry" shall be accountable
for allowed foam rubber capacity and any given the officially approved (Smiley-face) stamped License with fore head tattoo stating (I'm ok , your a terrorist)......!

PS: No duck-tape......! EeeeeK.!

[Vikingdad]

We did some modifications and continued the experiments today. First shots were tennis balls, getting about 200 yards out of them. The arrow/dowel/glow stick projectile is now DayGlo orange for visibility. Pressure is 150 PSI, same cannon. Started at a 10 degree firing angle and got 328 yards (apparently the distance last night was about 60 yards short of the 321 I said earlier- the range finder is hard to read at night so I think it was reading the trees behind the house).

Next shot was at 30 degrees and measures about 345 yards- measured on Google earth because there is now a hill in the way. We are rapidly approaching the property line, with deep woods on the neighboring property.

[orangello]

300+ yards seems like a safe distance to see if the boys can hit a bear in his jewels. (leave the truck running though)

[shaker]

We want a picture

[Vikingdad]

I'll put it on Youtube. The video is of the last firing. I failed to open the gate valve fast enough so it did not go off as well as it has. Past firings the thing goes off with a sort of "POP", this one doesn't do that. Also the projectile leaves the barrel much, much slower and wobbles on exit and a good shot will pop out of the barrel so fast you can't really see it until it is downrange a bit. The projectile landed far, far short of where we have been hitting and we lost it.

Video is here http://www.youtube.com/watch?v=5-iDXa1UZIs&feature=youtu.be

I'll make another one with the new projectile and upload it shortly.

[Vikingdad]

We made a new projectile with a rubber "cup seal" washer to get a tight seal with the barrel but have little drag. It works extremely well. We are getting about 390 yards out of this one. We only have about 15 yards before we are off the property (20 acres) and this is getting the greatest distance we can muster. The woods are pretty thick on the neighboring property, but we will try to get it down there after dark and use a glow stick to locate it.

Here is the latest projectile, view from the muzzle. http://www.youtube.com/watch?v=MXF8V3NPuz0&feature=youtu.be

[sdiver35]

Now if we could get a camera in the projectile, yes and launch it!

Fun project, keep us posted.

[Vikingdad]

They do make a rocket camera. My son has one that uses film and takes still photos. For that we would have to fire it straight up and have it deploy a 'chute. Its doable. I have seen digital video cameras for rockets too. So far we have been using scrap stuff.

Update, we attached a glow-stik and fired it after dark. Lost it though. We should have had someone downrange to spot it. Oh well, back to the drawing board.