I think your silencing ability is going to highly depend on what kind of flow your compressor outputs in a short amount of time. Suppressing a 1/4 gallon of air is going to be a challenge on a bbmg without the silencer being massive.

I can't think of anything cheaper that could be used for this particular application Bottle rockets are cheaper, and more efficient due to the capability of ejecting a liquid instead of a gas. Fun project though, it has been discussed lots of times on spudfiles. Any chance on a vid? Bottle rockets ...

boyntonstu wrote:Is there a simple way to measure the effect of tube thickness on velocity

I would guess you would pull each back to the same weight say 5 pounds then chrono them.

Try sprinkler.com there fittings are reasonably priced and shipping is a flat 7 dollars on most orders. Or you could see if you have a decent lawn care store in your area that does installs of sprinkler systems, they use high pressure water so all there fittings will at least be nsf pw sch 40 and in...

Zach1188 wrote:

THUNDERLORD wrote:Looks like a nice part and decent price considering.

"batteries not included" I'd get rechargeables or try to find the equivelent output as 8aaa's in a smaller configuration.

12 volts......I would do one 9v and two AAA's.

AA's the bigger cells will last longer.

There all right

jrddw's mom is mark.f who's alter ego is hotwired. She has some issues she refuses to listen to jrrdw unless he calls her Captain Underpants.

@jonnyboy: It's simply dividing kinetic energy by barrel volume - hardly fancy maths. It basically gives you an idea of how powerful a cannon is for its size, but it's not really a number of a huge amount of worth. Well it will at least give you a ball park estimate of what other cannons your is si...

What is the stored energy when the rod releases the 3 oz. weight?

I would guess the bend in the pole. So it's kind of is a slingshot already.

I remember a post where rag had done some fancy math to compare cannons of lesser size to larger cannons so even D_Halls Vera (massive hybrid) can be compared to a keychain gun. I can't find the post right now but I think the formula is in there so everyone could just use that and put it in there ca...

Very nice video Joerg! I'm sure PCGUY will make a separate forum and showcase for slingshots.

c11man wrote:i dont usualy shop at home depot but dont they have some 2inch nsf-pw and Home Depot?

At my store nothing is pressure rated past 1.5 inches.

My guess is 197 dollars.

Your not going to find nsf pw fittings at home depot over 1.5 inches.

Don't tap into an endcap use two pieces of chamber pipe to get to a suitable length then connect them with a tee fitting which reduces down to spark plug threads. Much easier and gives ideal spark placement. Spark plugs don't use NPT. Sorry I was under the impression that dyi's 20x cannon used an a...

@D_Hall: I didn't know spark plugs were so cheap since I never needed to buy one myself. I guess I'll just tap it into a small endcap. It certainly beats getting messy epoxy all over the place. Don't tap into an endcap use two pieces of chamber pipe to get to a suitable length then connect them wit...

Do you have any experience building piston valved pneumatic launchers? If you don't a small size marker gun even would give you and idea of what works and what doesn't. Take a look at the hybrid showcase I think dyi's 20x cannon matches your specs exactly except for the mix number. @ramses Contrary ...