Black Iron QEV Cannon

[pvcmaster]

Here is my almost completed black iron cannon. It has a 1 1/4" chamber, 3/4" QEV from McMaster, and the fill setup is a 1/4" schrader on a mini ball valve. The barrel is only temporary, as it is the only barrel-like thing i could find, but it fits nerf dart tag darts perfectly. I was able to put some through both sides of a cereal box at 110 psi, which i think is impressive for nerf darts. Future barrel will be copper and approx. 3 ft. long. Questions? Comments?

[lukemc]

Darn it! i made the chicken recipe and i cant read the last instruction. o well. nice cannon i cant wait to see it with the copper barrel

[jackssmirkingrevenge]

Looking good but the chamber is a tad small, especially if you'll be fitting a longer barrel - unless of course you're going for a shock-pump and 300 psi

[pvcmaster]

Im fine with it right now, but in the future I will probably get an 18 inch chamber instead of 12 inch.

[jackssmirkingrevenge]

If you're limited to 110 psi, 24 or more inches of chamber would do nicely, particularly if you have a large-ish diameter barrel. Run some figures through GGDT, it's really useful for telling you when you're simply wasting air by making the chamber any bigger.

[robert23]

That's sweet. I've been wanting to make a nerf sniper. I have to little pest brothers that I would love to get from about thirty feet.

[PVC Arsenal 17]

I have a question. Where'd you get a schrader with 1/4" threads? I saw them on McMaster but they were the long stem ones.

Also, how is the QEV qorking for you? Mine always leaks.

[mopherman]

I have a question. Where'd you get a schrader with 1/4" threads? I saw them on McMaster but they were the long stem ones.

Also, how is the QEV qorking for you? Mine always leaks.

have you taken it apart to see whats wrong? There could be crap in the seal.

[PVC Arsenal 17]

I'm too lazy.

[pvcmaster]

I found the schrader on the Ace website and had it delivered to the store:

http://www.acehardware.com/product/inde ... Id=1277973

It is really cool and i will be using it for a while on other cannons.

And no, my QEV does not leak, and i hope it never will.

[iknowmy3tables]

why do you have a ball valve on the schrader is it to prevent acidentalfiring during filling that pretty cool

the canon is near flawless like your other cannons but its time for you to start making your cannons more unique

[frankrede]

I have a question. Where'd you get a schrader with 1/4" threads? I saw them on McMaster but they were the long stem ones.

Also, how is the QEV qorking for you? Mine always leaks.

I got mine of mcmaster, exactly like that.

[pvcmaster]

I want to put this cannon into GGDT, but i dont know the valve specs for a 3/4" QEV. Could someone help me with this?

[jackssmirkingrevenge]

You could do it with a generic valve with nominal values (say flow co-efficient 50, opening time 10) and play with barrel lengths and chamber volumes - the performance values won't be realistic, but they will give you a rough guide to what works better than what.

[spud yeti]

looks really nice, well done.