Where are youse guys getting marbles that fit a 1/2" sch40 PVC pipe ?

I bought mine from a store called hobby lobby. They have all sorts of arts and crafts stuff they come in bags of about 100 for $2. Although they dont fit perfect in the barrel they are pretty close and work well. My cannon will ...

Yeah I plan on just putting a piece of 1/2 inch PVC into the top of the tee

So I am currently working on a QEV cannon and while I wait for my 3-way valve to arrive I decided I would start working on a breech loading design. Hopefully I am posting this in the correct section. Anyways here are some pictures of what I have made. I know some of the parts are a little sloppy at ...

At first I had the air fitting then a ball valve then a tee going into the pilot and also to a blowgun. This worked only when I shut the ball valve off after the gun was pressurized however simply leaving the ball valve open and pulling the air line off the quick disconnect would make the valve fire ...

I also forgot to mention I even tried venting the pilot with a 3/4 inch unmodified sprinkler valve. Although this did work it did not vent the pilot quick enough so the shots wernt as strong as when I just pull the airline off.

Yes sorry I guess I should have said that. There was a "tee" with a blowgun. But like I said it wouldn't fire without pulling the airline off anyways so I just simplified things and took off anything that wasn't needed. It appears that a 3-way valve is needed so I'm going to order one soon.

[img]<a%20href="http://s1106.photobucket.com/albums/h379/hoppins10/?action=view&current=IMG_20101121_200042.jpg"%20target="_blank"><img%20src="http://i1106.photobucket.com/albums/h379/hoppins10/IMG_20101121_200042.jpg"%20border="0"%20alt="Photobucket"></a>[/img]

Finally got some pictures [img]<a%20href="http://s1106.photobucket.com/albums/h379/hoppins10/?action=view&current=IMG_20101121_200036.jpg"%20target="_blank"><img%20src="http://i1106.photobucket.com/albums/h379/hoppins10/IMG_20101121_200036.jpg"%20border="0"%20alt="Photobucket"></a>[/img]

Another option is to add a 1/4 ball valve in your air line. Charge the chamber and shut it off.

I have done that and it works well. I guess im going to end up buying a 3-way valve just so the gun will fire easily. My goal is to make it semi auto but I wanted to get all the kinks worked out of the ...

so before buying a 3-way valve, i experimented with an UNMODIFIED 3/4 inch sprinkler valve i had laying around. It was discouraging that even with a sprinkler valve on the pilot side it still didn't actuate the QEV as well as if i just pull the airline off and let it dump out the air fitting. I am ...

Have you considered fitting a spring to the QEV and adding a small equalisation hole, then feeding air through the chamber side?

Damn sight cheaper than looking around for a 3 way valve Here's an example of the concept, courtesy of Brian the Brain.

I have considered doing this. I took the valve ...

So it only dumps the pilot area so the gun fires?

I was looking at some CAD drawings made by dewey-1 and noticed one of his drawings http://sketchup.google.com/3dwarehouse/details?mid=cc343d25db8b97788b92e236cf9045a7&prevstart=0 had which looks to be an air inflator hooked directly up to the pilot side of a qev. My question is does this act like a ...

Thanks. That thread helps out tremendously!!

If your airline is filling the pilot area at a faster rate than the blowgun can empty it, the QEV will never fire.


Thats what i think is going on here. The blowgun can not flow more air then being supplied by the compressor so it never fires. The ball valve can flow more air than being supplied ...