"AA" Coaxial Piston

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frogy
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Fri Jun 30, 2006 1:35 pm

"AA" COAXIAL!

Cannon Name- "AA" Coaxial
Type of Cannon- Coaxial Piston Pneumatic
Chamber Size- 1.033" x 10.5" (11.924337460912747 ci.)
Barrel Size- .608" x 12" (13.936004480360324 ci.)
Gas Source- Compressed air
Valve- Barrel Sealing Piston, 1/4" Ball valve for pilot
Coaxial obviously, uses high-performance DOW33 lithium-soap lube
Constructed for shooting "AA" batteries...
New concept (as I know)- Hot glue based piston...
C:B ratio is .855:1

This gun needs tweaking to work...

This gun was mainly made becuase I stuck a enormous case of dead "AA"s... It was like burried behind my shed :D Arggggh, tresssure :lol:
And to test 1" pistons for barrel-sealing T usage...

Gun "completed":
<img src="http://img73.imageshack.us/img73/96/aacoaxialao5.jpg">

Piston close-up:
<img src="http://img517.imageshack.us/img517/5224/piston8vx.jpg">

Off-center barrel, help please:
<img src="http://img73.imageshack.us/img73/5235/o ... relvj8.jpg">

<a href="http://img457.imageshack.us/img457/2807 ... ton1tq.png"> Here's my concept drawing... </a>

The close up of the piston makes me kinda dizzy because it's at a weird angle, but you can tell what it is...

It's a Hot Glue piston, it seals the barrels about perfectly and the chamber almost %100, I think I need to drill equalization holes because it seals so good...

I cut a small section of 1" pipe, taped magazine paper (glossy) across the bottom of the pipe, sprayed the inside with Cooking spray and them whiped out excess spray and them put in about 2.5 sticks of hot glue....

Let it cool, rinsed in cold water, cut off top and bottom small peices to help flatten, sanded with 320 grit sandpaper... I was using Dow 33 (thickened lithium soap) for a lube, but it slides nicely on it's own... Since my guns going to be able to come apart maintence wont matter...

The piston doesn't seal with the barrel, probably mainly because the barrel is so off-center, but I'm first going to put neopreme on the piston, this is a pain in the ass, but it's fun and gave me an excuse to buy a ball valve...
Last edited by frogy on Tue Jul 18, 2006 11:03 am, edited 4 times in total.
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)DEMON(
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Fri Jun 30, 2006 1:38 pm

Is that all of the gun?

(I posted this befor he finished his gun)
Last edited by )DEMON( on Tue Jul 18, 2006 11:58 am, edited 1 time in total.
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frogy
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Fri Jun 30, 2006 1:47 pm

I still need the 1" to 1/2" bushing, and I also need an 1" to 1-1/4" adapter, a 1-1/4" Male, and a 1-1/4" Female Cap...

I went up to 1-1/4" so the piston will be removable, it won't fit through a 1" Male....

Edit:
Guns finished now
Last edited by frogy on Tue Jul 18, 2006 10:09 am, edited 1 time in total.
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Atlantis
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Fri Jun 30, 2006 2:37 pm

For the hot glue did you put the pipe in the oven, or did you use the glue gun to melt it? I tried the gun but it came out really wierd.
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djt
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Fri Jun 30, 2006 3:19 pm

im pretty sure he would have to do it all at once or it woudlnt be even.
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PVC Arsenal 17
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Fri Jun 30, 2006 3:50 pm

I made a discovery recently.

3/4 caps and couplings fit almost perfectly in 1 1/4 pipe. Maybe good for a piston.

The hot glue piston looks cool though.
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noname
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Sat Jul 01, 2006 10:46 am

Looks good, but you still need a paintjob. Also, what are you planning to use to exhaust the piston? You should cut the end off if you don't want weird looks from people on the street. They'll think you just feel like carrying around a piece of pipe if you do.
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frogy
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Sat Jul 01, 2006 6:59 pm

PVC Arsenal 17 wrote:I made a discovery recently.

3/4 caps and couplings fit almost perfectly in 1 1/4 pipe. Maybe good for a piston.

The hot glue piston looks cool though.
The smart people know that Caps fit in the pipe, most people don't check, good job for being smart :D

I like the hot glue gun piston too, it slides very very well...

I'm not sure if the piston will seal %100 how it is, but in my test so far it has, since the guns not done I don't no, and since I can't drive I don't know when I'll get to Home-Depot :(

I'm probably going to use a blowgun or ball valve for filling and exhaust, most likely a ball valve with a male quick disconnect on one side...

Since the guns going to be disassembleable (sp?) I'm mainly making it for testing 1" pistons that I'm going to use in 1" barrel sealing Tee's...

Well and for shooting AA's really far :)
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Benny
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Sat Jul 01, 2006 8:32 pm

by "cooking spray", do you meen olive oil cooking spray?
Join the spudshot forum!!!!!

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ProfessorAmadeus
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Sat Jul 01, 2006 8:52 pm

I think he means pam or other stuff like that.
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mark.f
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Sat Jul 01, 2006 9:19 pm

Why not place a rubber sealing piece on the front to seal better? If you can't go get neoprene from the hardware store, slice open an old soccer ball to get the rubber.

And you don't <B>need</B> a paintjob.
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Benny
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Sat Jul 01, 2006 9:24 pm

Mark, He Said It Seals Fine. Why Would He Need Neoprene If It Already Seals.
Join the spudshot forum!!!!!

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noname
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Sat Jul 01, 2006 11:06 pm

He doesn't need neoprene but it would be nice to have in there just in case.
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frogy
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Sun Jul 02, 2006 10:09 am

I'll draw up a concept design and put it in the first post to show you guys how my piston will be removable from the gun incase it doesn't seal right....

They sell Neopreme sheats at McMaster and Home-Depot so probably anyone could get them.... If it seals bad I'll just mod my piston....
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frogy
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Tue Jul 18, 2006 10:15 am

What kind of neopreme should I get at McMaster\Home-Depot...

Where can I find it at Home-Depot

What thickness?

The guns "done" now, but it doesn't work, please give me suggestions to fix my barrel problem...
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