SpudFiles

i have made my first pneumatic cannon, created from pics of the PB rifle, and the gb cannon that are posted in the pneumatic section. It has a 3/4 in modded sprinkler valve, and i followed the how to very precisely. However, when i put air in through the schraeder valve, it does not build up pressure in the chamber as it should. it gous right through the valve and makes a noise like a muffled air horn. does this mean that my sprinkler valve is defective or perhaps some other flaw that i made? please help me if you happen to know what is wrong. thanks a ton.

that happens a lot, we usally say:

clean out all the pvc dust!! always wash the pipes b4 putting on the valve.

its that simple to fix it? i tried cleaning it already, but that didnt do anything.

The air is going in so fast that it doesn't allow the valve to seal. Try letting in air slowly, untill about 30 PSI.

Either that, or your pilot is somehow open.

whats my pilot? and how do i check if it is open?

As to what a "pilot" is, check the <a href="http://www.spudfiles.com/spud_wiki/index.php">wiki</a>.
As to how you check if it's open, all shalt become clear once you learn what it is.

my camera is really horrible and i had a hard time just getting it to work for these pics...

Sorry I proably forgot to tell you in the PM message I sent you but could you also provide a pic like ng001.jpg but with out the diaphram on it (rubber thing). Cant see really but is there a spring inbetween the valve top and the rubber diaphram? (or did you take it off for the pic?) If not thats is your problem.

In the picture below where does the spring sit? Does it sit in the red circle or the blue circle? (Im pretty sure its the red one)

Oh my god, your pilot volume is huge. A bit off topic, but that's really hindering performance. Cut that hose down to less than a foot, and you'll notice a big difference in power.

well, its not even working at all, so i have no power, lol. Yes, the spring sits in the red circle, i just took it out for the pic.

what i think is happening is that since you have such a long hose for ur pilot its taking such a long time for the air to neutralize that its not working. try threading the blogun directly to the valve, and taking the nozzle off the blowgun

ahh, good point. the reason behind the long hose is that i had not gotten the correct fitting yet, but i have it now. I will try that now.

[quote] pimpmann Sorry I proably forgot to tell you in the PM message I sent you but could you also provide a pic like ng001.jpg but with out the diaphram on it (rubber thing).

can i take the rubber diaphram out? i seems to be factory glued or something, is it ok to take it off and will i bea able to get it back on properly? also, i removed all of the hose from the blowgun and attached it directly to the sprinkler valve, but that still did nothing for allowing pressure to build up in the chamber.

All the vavles Ive worked with you can take the rubber thing out. Try to give it a little force to come out but if its not going to come out your right obviously its connected so how, so do take it out. Is there a rod going through the plastic part in the middle of the diaphram? Cant remeber if I already asked you but is the equlization hole clogged?

well, would you mind reminding me which is the equalization hole? and there is no rod or anything above the phram , just the spring and then the modded cover/top. once again, thanks for helping me troubleshoot guys, especially u pimpmann. I'm just kinda pissed off because I really want it to work.