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new piston gun now with damage pics

Posted: Fri May 11, 2007 7:13 pm
by super spuder
I have finally finished my piston gun. It has a 25 inch long by 3 inch chamber. The barrel is a 1.5 inch pipe that is 80 inches long. I just ran it through GGDT and it says about 827 feet per second The piston is 2 hockey pucks with duck tape wrapped around them. I am going to get a better piston for it some time in the future. The fill and release of the piston part is done via a moded blow gun (thank you chaos) and the main chamber is filled via a quick coupler. If you have any questions pleas feel free to ask. And yes it is made of DWV parts :oops:
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i will have some damage shots after the glue sets :D that is if it works :roll:
Edit: it works great
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that big hole/dent is in 1/2 inch press board at 70-80 psi

Posted: Fri May 11, 2007 7:37 pm
by experament-u2
wow thats a nice gun
but im not sure about the DWV parts but hey each to his own
the one thing i love about this gun is its all vented by a tiny blowgun :D

Posted: Fri May 11, 2007 7:43 pm
by super spuder
I don't know about the DWV parts either, but i have left that piece of pipe (before it was a cannon) pressurized to 125 psi, and it did don't blow up. That blow gun is moded, but i am still not sure that it will vent the chamber fast enough? I just put it on because it acts like a handle and is easy to aim and shoot with :D

Posted: Fri May 11, 2007 7:59 pm
by hi
I truly admire you... not because the gun is spectacular, but because you are just so cool for using DWV ABS :lol: . i think you should get some sort of award.

i also dont think that you should replace the piston, it rocks....

EDIT- you NEED a bumper!!!! i dont know if you have one, but you NEED one. dont fire it without one or bad things happen. maybe a spring and half a tennis ball with foam would do it. it may sound like over kill, but you need it.

edit edit- i also like how you mounted the blowgun backwards.

Posted: Fri May 11, 2007 8:08 pm
by super spuder
:lol: thanks hi. Yea, i am too cool for that crap , more like i am to pour for it hehe. But yea, if the piston actually stays togather, i probly wont change it. But i am not sure the duck tape will stay sealed for long :roll:

edit: i mounted it backwards because i needed to fill it from the same blow gun, so i supper glued the screw in piece of the blow un in and screwed the blow gun on :) then just used the regular chuck on the other side

edit edit: i do have a bumper. i just did not take a picture of it.bumper= 3 springs and stick on foam.

Posted: Fri May 11, 2007 8:41 pm
by turbohacker
Cool gun, Is this you firt piston gun?- If so welcome to the real world of Pnumatics :D
I give you props fo the blow gun idea, very smart
did you mod it? I tryed to mod one once and ruined the blow gun :oops:

Posted: Fri May 11, 2007 8:46 pm
by super spuder
yea, first piston gun, got tired of ball valves. Yes the blow gun is moded. it made it flow about 40% better.

Posted: Fri May 11, 2007 9:09 pm
by noname
This gun will not fire. That's a chamber sealing piston valve, and doesn't have O-rings.
You are also a dumbass for using non-rated ABS DWV parts, probably cellular core. ABS WILL BLOW OUT OVER TIME, just give it a while. In the meantime, try to make a gun that will shoot.

Posted: Fri May 11, 2007 9:13 pm
by Slugfoot
Nice cannon. But er....will the blowgun hold pressure that way round? I thought they had to go the other way otherwise the air pushes the valve open. I could be wrong.

Posted: Fri May 11, 2007 9:14 pm
by super spuder
@ noname thank you for that insperational post :D and i dont know if the blow valve will hold presure that way either. i will find out 8)

Posted: Fri May 11, 2007 9:54 pm
by Velocity
Its not necessarily a chamber sealing valve... it could be an indirect linear piston exhaust cannon (check out plasticex's cannon on his homepage.

This is a very nice gun, but I unfortunately have to agree with the other people: you need to replace those parts. ABS DWV parts cannot hold pressure, and it will fail. Also, the piston is probably too heavy; you might want to consider looking into a lighter piston, and also one which would seal in the piston seat better.

Posted: Fri May 11, 2007 10:01 pm
by frankrede
I am speechless, someone with 300 posts here, and this?
wow.
You should have researched better.

Posted: Fri May 11, 2007 10:03 pm
by super spuder
The piston is not that heavy actually. edit @ frankred. i did research but i can not get pressure rated parts within 60 minutes (one hour) of my house any bigger than 1.5 inch. and as for the piston. i have a better piston planed. but i do not have the tools right now to make it.

Posted: Fri May 11, 2007 10:04 pm
by noname
Rmich, I'm unfamiliar with it. Do you have a link to the page?
I also doubt that he's familiar with it either, considering I've been here over a year and barely miss anything. I wasn't on Spudtech much though.

Posted: Fri May 11, 2007 10:19 pm
by Kenny_McCormic
hi wrote:I but because you are just so cool for using DWV ABS :lol: . i think you should get some sort of award.
lol yea a darwin award