MG-15

[Carlman]

Hi all,

Im new to this forum although i have been scouring it for the past week and a half looking for ideas. This is my first cannon i have ever built and i designed it myself. Below are the specs:

Chamber: 450mm of 50mm uPVC pipe PN18
Valve: 25mm modded sprinkler valve, piloted by a blowgun
Barrel: 900mm of 15mm uPVC pipe PN18
Fill Valve: Threaded chrome shrada valve

It features interchangeable barrels from 15mm to 20mm and 25mm. Soon to come is a zoom scope and red laser as well as a bipod. It is powerful, from what a noob can tell anyway lol, can put a marble through my tin shed at 50psi, havnt had a chance to test distance or high pressures as im in surburbia but i have acess to our 5 acre block an hour away soon, ill get vids and pics of damage.

This is the whole gun with the marble barrel attached.


This is the trigger and valve setup


This is a different view of the whole gun


I am yet to decide on a name, any sugestions are very welcome. Feedback is encouraged aswell, thnx.

Carl.

**EDIT**:

Below are some damage shots with marbles. Distance and psi shown above each picture. Higher psi, better targets and larger distances could not have been done this time round as i have crap neighbors but will get some good stuff up soon.


40psi - 20m - Marble against fishing sinker



60psi - 20m - Marble against fishing sinker



80psi - 20m - Marble against fishing sinker



25psi - 10m - Marble against Coke cans


Sorry about the ppor quality of the pictures, they were taken with my camera phone.

In the next few days i am modding a new valve with a higer flow rate and overall better construction, making some camo sleeves out of an old ozzie army uniform (and due to popular demand taking the tape off), constructing a bipod and shooting stuff!

[The Kid]

looks good for a first cannon, loose the tape tho i makes it look like crap and btw r u aussie

[mark.f]

Location: Western Australia

Nice cannon, although I would loose the tape as well.

I would also worry a little about that front coupling/reducer combo. They look rather shallow...

[jrrdw]

What rating pipe is "uPVC pipe PN18 "? I get confussed easy!

[Los Frijoles]

Most reducers are DWV. Are you sure that fitting is pressure rated?

Nice cannon, I won't say what has already been said about the tape

[Carlman]

the tape looks pretty crappy in the pictures, looks alot betta in real life. its not permanent tho dnt worry, im gettin some army scrim to cover it with for that tru blu bush sniper look! But yea i quite lyk the tape nd thts wat mattas aint tht rite aye?

nd yea im an ozzie...AUSSIE AUSSIE AUSSIE, OI OI OI!!

name sugestions?

and ALL fittings on thr are pressure rated PN18 NO DWV WHATSOEVER

i think PN18 is lyk the US SCH 80, correct me??

[mark.f]

Beans, most reducing couplings are DWV, not most reducers, (another name for bushings). I was just saying they looked rather shallow, but Carldude already said his parts were all pressure rated.

I think PN means pressure number, correct, and the number corresponds to the rating in bars?

[SpudUke5]

Nice but you just gotta make sure that you next time dont use dwv fittings if they are and you gotta cut down on the pilot volume (hose) before JSR comes to tell you.

JSR in
3......
2......
1......

[mark.f]

Hi!

Just so we're clear, pilot volume won't be cut down too too much by cutting that hose. I've found most sprinkler valves aren't that sensitive to pilot volume size as are piston valves and Q.E.V.'s. I remember Joel's cannons having around 6-7 feet of hose going from a blowgun to the sprinkler pilots on his Supah-Valve launchers.

[jackssmirkingrevenge]

Just so we're clear, pilot volume won't be cut down too too much by cutting that hose.

I can someone with a chrono (or some other arbitrary way of measuring power, stackned sheets of 1/4" ply for example) and a sprinkler valve launcher try various shots with different hose lengths and quantify the difference in performance? If the difference is only a couple of feet per second then I've been bleating about hose length for nothing, but I think it will be more than that.

[nivekatoz]

The tape has to go !!!!!!! I think it would look cool if you were to paint it black...Insted of using regular paint you should use truck bed liner paint, that stuff is strong.......I would use the spray stuff,not the brush on stuff...

[mark.f]

I don't think sprinkler valves are too sensitive to pilot volume, JSR. I'm sure there's SOME difference, but I don't think it'll be that significant, like if you were to leave a huge-arse piston travel in a piston gun, or have all sorts of tees and junk on the pilot side. On a homemade piston gun, air equalizes, (usually, unless the valve is designed with one-way equalization and a good non-static seal), back into the pilot volume during firing. Not so much on a sprinkler valve or most Q.E.V.'s.

That'd be a good idea to test it. I don't have any hose lying around ATM, though. Plenty of compression fittings w/ tubing inserts, and hose barbs, but no hose, sadly. Got the perfect gun to test on too.

[MrCrowley]

What rating pipe is "uPVC pipe PN18 "? I get confussed easy!

PN18 = 261PSI


Nice cannon by the way, looks like a fun plinker. And yeah lose the tape

[f.c]

i have two sections of pn18 and there rated to 261 psi. im just saying this to back up mr crowley.

[Maniac]

good gun for your first pnematic man i love it and i think weve said enough about the tape. also shorten the hose it can only help.
what is that sprinkler valve brand it looks like it has a guide rod because you have the barb sticking out the side