Endeavors In Lunacy Or
#1
Posted 18 February 2009 - 09:07 PM
Basically, it's just a 1-1/4" Sch80 male pipe coupling to 3/4" FIP adapter. Shove the ball inside the 1-1/4" end, and use a couple to the 1-1/2" pipe over the end. Unfortunately this requires removal of the barrel each time we load a new ball. Oh, well.
The tank is aluminum, and actually from an old fire extinguisher that my father had laying around (for twenty-five years, go figure).
It took a while to locate a fitting that would work in the end of the tank, because it's a wonky thread pattern. I finally found that a CGA580 fitting (used for argon, helium, and nitrogen tanks) fit nicely, but still leaked. At first i tried using plumbing goop, but it leaked after a while.
Then I used epoxy instead. Seems fine up to 140PSI. Before installing the fitting in to the tank, I had my father bore out the inside wide enough to accept a male 1/2" threaded to 1/2" copper pipe adapter, then soldered the two together. Then I added the liquid epoxy to both sets of threads and screwed them together tightly.
While the epoxy was curing, I moved on to the next section, the 'T'. In reality, the 'T' is the body of an over pressure relief valve from an old water heater. I removed the internal of the valve and drilled through the chamber with the largest bit I had, a 5/8". In the end where the lever used to be, I bored out the opening a little more to accommodate a 1/2" Copper FIP adapter, and soldered them together.
After the epoxy cured for 24 hours (just to be safe), I screwed together the 3/4" Ball valve, 'T' fitting, pipe nipple, barrel adapter and the tank assembly.
I actually made my own 3/4" MIP to 1/8" FIP bushing, though I probably could have bought one. But I had the plug, the drill bit, and the tap, so... The second cross fitting is another I made myself. Originally a 1/8" FIP, 1/8" FIP, 1/8" MIP 'T', I drilled a hole in the side and soldered in de-rubbered tire valve. If you decide to solder a tire valve to something, do make sure to remove the Schraeder valve prior to the soldering, and then reinstall when cool. After construction, I assembled the cross with the tire pressure gauge ($4 at Carquest), a plug in one female port (for use later... muahaha!), and screw the whole thing in to the big 'T' fitting. For the barrel, I am using about one foot of 1-1/2" Sch40 PVC. ABS works okay too, but the cheap black coex stuff actually had an oval cross-section and was not suitable for a barrel.
Ammunition:
I like using the yellow foam golf balls from Target, rather than the multi-colored golf balls from K-mart, or nerf balls. They are a little heavier at 12 grams, than the four grams of K-Mart balls and five grams of Nerf balls. But they also fit perfectly in 1.5" SCH40 PVC, where nerf balls want thinwall, and K-Mart balls are smaller yet and want thinwall 1.25" PVC. Target seems to have recently switched from the harder foam balls that I have, to a softer, squishy foam ball. They feel about the same mass, but I have yet to purchase or try any of them to see how they perform.
I need to do a detailed analysis of relationship of pressure to distance for each type of ball I have. So far, at 30 PSI (well within bike or ball pump range), I can get consistent 50-60 foot shots. At 60PSI, I get about 90-100 foot shots. At 130PSI, which is what our shop air compressor runs at most of the time (125-140PSI), the ball goes farther than I can measure.... Let me put it to you this way: My lot is 126 feet long. From the back of the lot at the alley, I can shoot a 12 gram foam ball across the street, beyond the front of the neighbor's house. At LEAST 150 feet. Maybe this weekend I'll take a video of it shooting.
[15:51] <+Rhadamanthys> titties
[15:51] <+jakejagan> titties
[15:51] <+Lucian> boobs
[15:51] <+Gears> titties
[15:51] <@Draconis> Titties.
[15:52] <+Noodle> why is this so hard?
#2
Posted 18 February 2009 - 09:26 PM
Is it accurate though? I know with the NERF balls, they tend to "float" more than 'fly" is this true with the yellow golf balls? (I play golf and when I hit the practice balls with a little to much backspin they float like no one else's business)
-Loni
Edited by loni, 18 February 2009 - 09:28 PM.
#3
Posted 18 February 2009 - 10:09 PM
#4
Posted 18 February 2009 - 10:27 PM
Awesome, I didn't know that Target had foam golf balls. I'll have to check them out. K-Mart's balls have shrunk since the first time I started using them, so I'll have to check Target's out.Ammunition:
I like using the yellow foam golf balls from Target, rather than the multi-colored golf balls from K-mart, or nerf balls.
#5
Posted 18 February 2009 - 10:51 PM
K-Mart's balls have shrunk since the first time I started using them, so I'll have to check Target's out.
I'm sorry, but oh man...
Edited by flyingchicken, 18 February 2009 - 10:56 PM.
#6
Posted 18 February 2009 - 10:59 PM
Awesome, I didn't know that Target had foam golf balls. I'll have to check them out. K-Mart's balls have shrunk since the first time I started using them, so I'll have to check Target's out.Ammunition:
I like using the yellow foam golf balls from Target, rather than the multi-colored golf balls from K-mart, or nerf balls.
Target's balls are a pretty good deal, too. Usually $7-ish for 12, if I remember right. Target.com has them at $19.99 for 36.
[15:51] <+Rhadamanthys> titties
[15:51] <+jakejagan> titties
[15:51] <+Lucian> boobs
[15:51] <+Gears> titties
[15:51] <@Draconis> Titties.
[15:52] <+Noodle> why is this so hard?
#7
Posted 18 February 2009 - 10:59 PM
It's not every day that you get to say, "K-Mart's balls have shrunk", so I intend to take advantage of every opportunity I get.Nice homemade. It would be cool to launch balls from long distances (wow).
K-Mart's balls have shrunk since the first time I started using them, so I'll have to check Target's out.
I'm sorry, but oh man...
#8
Posted 18 February 2009 - 11:09 PM
K-Mart's balls have shrunk since the first time I started using them, so I'll have to check Target's out.
I'm sorry Carbon, but I have to sig that.
#9
Posted 18 February 2009 - 11:10 PM
If at first you don't succeed, add more epoxy.
#10
Posted 19 February 2009 - 05:46 AM
I'd be good for some competition I have been llooking for a reason to start building cannons again. What kinds of restrictions would be in place? Also is there a chance of a prize?I would like to participate in some friendly competition at launching ballistic balls, but we'd really need to decide on a consistent standard ball that's obtainable for everyone.
My combustion cannon would send real golf balls (5 or 6 at once) to almost 190' but it's likely to be harder to achieve such range with foam's drag-to-weight ratio. I might get close to 300' with as many foam balls as can fit in a pringles can, but that would be cheating, because I expect they'd stay in the can almost the whole way.
#11
Posted 19 February 2009 - 08:44 AM
Thanks Draconis for this, I've been needing some ball gun info for a project of mine. Good work.
But you can totally shoot Vacc there, he loves it!
~Talio
#12
Posted 19 February 2009 - 02:55 PM
I'd be good for some competition I have been llooking for a reason to start building cannons again. What kinds of restrictions would be in place? Also is there a chance of a prize?I would like to participate in some friendly competition at launching ballistic balls, but we'd really need to decide on a consistent standard ball that's obtainable for everyone.
My combustion cannon would send real golf balls (5 or 6 at once) to almost 190' but it's likely to be harder to achieve such range with foam's drag-to-weight ratio. I might get close to 300' with as many foam balls as can fit in a pringles can, but that would be cheating, because I expect they'd stay in the can almost the whole way.
I'm thinking pressure restrictions, like having a relieving regulator attached at the fill point, or maybe short barrels too. With a 6" long barrel, distance seems to top out about 60-70 feet. And accuracy fails the higher you push the pressure.
[15:51] <+Rhadamanthys> titties
[15:51] <+jakejagan> titties
[15:51] <+Lucian> boobs
[15:51] <+Gears> titties
[15:51] <@Draconis> Titties.
[15:52] <+Noodle> why is this so hard?
#13
Posted 19 February 2009 - 07:33 PM
I probably couldn't do it unless you set up an air compressor. Even if they aren't very mobile though they are insanely powerful. So what I was into spud guns before nerf.Veg, we're gonna start incorporating a ball gun round or two into future SENOs. Perfect time to bring out a cannon for demo.
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