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First 2" piston valve

Posted: Fri Apr 27, 2012 7:46 pm
by kotabuuki
Wow, it's been a year already? It seems like only yesterday I was asking noobish questions, but alas it is complete. It was originally for a physics project. Other students also made potato cannons but they were spray and pray, and in a head to head competition it blew them away. The reason I've not gotten around to it yet is because i just painted it this past week, and I'm in college now, and I'm going for mechanical engineering, so time is scarce.

Anyways, first and foremost, thank you to POLAND_SPUD, Technician1002, Gun Freak, saefroch, and mark.f for dealing with my stupidity and endless questions.

Specs:
It's a 2" piston valve with a 1.5" sealing face.
The piston is solid a solid acrylic rod with rubber on the front to help produce a seal.
The black chamber is 3"x18".
The larger chamber is 3"x30".


Barrels:
Black 54" sdr21 1.5"
Shorter 40" sch40 2.5"
Shrouded 2" X 60"
Last 60" X 1.5" sch40

Unfortunately I have no damage pics. I live in a residential area, within city limits, and on top of that I live on a hill that people like to speed on, so the police like to sit in my neighbors driveway and hand out tickets. I know it's not illegal to have one in my state, but it's not legal to shoot it within city limits, and my local law enforcement like to hand out tickets for any reason possible. I've only shot it once at home, and the one time I did I shot a golf ball through 2 (scrap) aluminum garage door panels, it hit a piece of pvc I was using to prop them up and then proceeded to almost take out a neighbors bay window so I won't be doing that again. I have a friend with some land that I plan on visiting soon so I may have damage pics. (If I remember a midst the excitement).

Side Notes:
The barrel support is made of acrylic; and Yes I know the barrel support is not touching the barrel. When I had it made I measured wrong and it's 1/4" too short. I'm having a friend cut another out when he has the time.

Also, lacrosse balls fit perfectly inside the 2.5" barrel; just add some sort of lube to break the friction and your in business (that's what she said).

Also, Also, I have a sprinkler valve that goes on it but I don't want to paint it, and it doesn't go with the color scheme so I decided to leave it off.

Also, Also, Also, the bi-pod stand can also function as a fore grip.

And lastly, the reason i'm not using the larger chamber is because I have a small air compressor and it just takes too long to fill.

Any questions, criticisms, or comments are welcome.

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Posted: Fri Apr 27, 2012 8:03 pm
by Gun Freak
Nice :) I also underestimated and was surprised by the power of my first golf ball cannon... I never again took a "test shot" at my wooden fence :D

Posted: Fri Apr 27, 2012 9:21 pm
by mattyzip77
Nice job and that paint is pimp!!! Can we get some shots of the insides and the piston??

Posted: Fri Apr 27, 2012 10:22 pm
by kotabuuki
mattyzip77 wrote:Nice job and that paint is pimp!!! Can we get some shots of the insides and the piston??
This is before I painted it but it'll do.

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Posted: Fri Apr 27, 2012 11:25 pm
by jackssmirkingrevenge
Very nice :)

Did you think about hollowing out then capping the piston? I would add a bolt and washer to keep the sealing face well in place too.

Posted: Sat Apr 28, 2012 12:25 am
by Technician1002
I like to have the opening centered in the T when open for better flow. As this photo shows, the valve when open has an off center opening. This style does have an advantage though, a shorter piston can be used. Which is better, I don't know.
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Posted: Sat Apr 28, 2012 9:33 am
by kotabuuki
jackssmirkingrevenge wrote: Did you think about hollowing out then capping the piston? I would add a bolt and washer to keep the sealing face well in place too.
I wouldn't modify my piston at all. Acrylic can be very brittle and I think that modifying it at all would compromise it's integrity. I already had it crack a little at the bumper end so I'm going to have to make another soon, but it still functions fine. If anything I would just make a delrin or bolt style piston.

Technician1002 wrote:I like to have the opening centered in the T when open for better flow. As this photo shows, the valve when open has an off center opening. This style does have an advantage though, a shorter piston can be used. Which is better, I don't know.
Yea.. I know it's not centered, I was in a hurry and measured wrong when I glued it in, but it seems to be working fine.

Posted: Sat Apr 28, 2012 3:59 pm
by mattyzip77
I think you should paint the sprinkler valve dude. It will make it look way better and cooler with it on there. Also, is the sprinkler valve modified???

Posted: Sat Apr 28, 2012 4:26 pm
by kotabuuki
mattyzip77 wrote:I think you should paint the sprinkler valve dude. It will make it look way better and cooler with it on there. Also, is the sprinkler valve modified???
Yes of course. Blow gun and all.

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