SpudFiles

The first one I built used a huge 4" chamber, and only one sprinkler valve to dump air to the barrel. Lots of wasted air. That is the first video.

Nothing special about it, it works.
I redid the design with a 3" chamber, and two sprinkler valves. The threaded fittings allow for adjustment to keep the barrel and chamber parallel, even if I change to a smaller diameter barrel. For high pressure launches (50 psi to an estimated 70 psi the barrel and chamber should be tied together. It doesn't matter on lower pressures)The chamber is filled with a CO2 tank and regulator that fills to about 55 psi max, with a ball lock disconnect. I'm a homebrewer, so already had those parts. If I want higher pressure (not needed for fetch), I'll cautiously top it off with a 12g CO2 cartridge. Bring it to 50 psi, then about 6g more from the cartridge.

I deserver points for ugliness on the paint job, I'll probably go over and make it all tan in the future.

The barrel I purchased from a vendor. It is breech loading. Unfortunately it is not round on the interior, and impossible to load a tennis ball from the front. The ID is 2.41" in the narrowest part. Overall too tight for tennis balls, but a sack of oranges in the approximate diameter are a lot of fun to shoot.[youtube][/youtube]
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My favourite, done at White Sands, you just can't see where the ball lands...
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nice, i like the paintjob . only it has lots of death space...

Nice one! I like the layout and agree with the paint job. It does have a bit of DEAD* space but i doubt it hinders performance to much.

Good work

Wish I could head out to White Sands and cut loose...

Nice work and boy oh boy your dog looks like it gets disapointed when it can get/fetch the ball.

Welcome to Spudfiles.

death space

Jake, you're my hero.

The cannon looks good, guy with a dog who likes tennis balls. The dead space isn't really too much of a problem in this circumstance since this build isn't centered around destructive force. The only thing it hampers is your efficiency. But who cares, it looks like a fun toy for your pooch, and yourself.

What do you mean you have an ugly paint job? I have that same paint job on my first pneumatic I ever built

Thin wall pipe works well for tennis balls. The paint job is fine. Instead of repainting all tan, simply add a couple more tan earthtone colors to make a great desert camo paint job. Looks good. A single larger sprinkler valve can have a better flow rate than 2 smaller valves in parallel and simplifies the plumbing. For using what you had on hand, nice build.

poor dog-all those balls flying into the stratosphere-never to be seen again. love the idea!

LOL @ failed fetch attempt! I had a similar situation when I launched a potato for a guy with a shotgun to shoot the spud as skeet, and he just looked at me after I launched it with a blank stare on his face.