Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 61 users online :: 4 registered, 0 hidden and 57 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Pengun piston

Post about things you have launched or thought about launching. Also post about various materials used for building cannons. No posts about explosive projectiles!
Sponsored 
  • Author
    Message

Pengun piston

Unread postAuthor: Gun Freak » Fri Oct 15, 2010 9:06 am

I want to use a pencil eraser for a piston because it fits tightly but I don't know if it will hold up to 400 psi without the barrel becoming a cookie cutter. I couldn't find any rubber stopper that would fit well at the hardware store either, so what do you think?
:occasion5:
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Unread postAuthor: Crna Legija » Fri Oct 15, 2010 9:27 am

you could add something to the barrel to increase its wall thickness but a rubber would still get cut up bad or put the seal on the barrel just have a flat hard piston
  • 0

'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
User avatar
Crna Legija
Major General
Major General
 
Posts: 2333
Joined: Sun Jul 20, 2008 5:14 am
Location: australia
Reputation: 0

Unread postAuthor: Gun Freak » Fri Oct 15, 2010 9:34 am

Ok, I might find something to put around the barrel, but my barrel is to wide to integrate a seal onto it and have a hard piston. There wouldn't be a lot of room around it for the air to flow.
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Unread postAuthor: saefroch » Fri Oct 15, 2010 4:57 pm

At 400psi, with multiple uses, your piston will probably get torn apart. Erasers, after all, are designed to do so. :wink:

I'd model the forces on the eraser with some weights and see what happens.
  • 0

User avatar
saefroch
Major General
Major General
 
Posts: 1679
Joined: Mon Jun 08, 2009 8:47 am
Location: U.S.A.- See Map
Country: United States (us)
Reputation: 0

Unread postAuthor: Gun Freak » Fri Oct 15, 2010 5:12 pm

I already did, but without weights. Just the force of my hands got a circle etched into the front of the eraser. I'm thinking cast epoxy now with some neoprene on it but will the rubber stay on if I just epoxy it?
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Unread postAuthor: clemsonguy1125 » Fri Oct 15, 2010 5:24 pm

Heck no, is wont last 200 psi, I already have a thread about this. What i did was use a vinyal keychain and use the chamber to cut the piston out, like JSR.
  • 0

User avatar
clemsonguy1125
Major General
Major General
 
Posts: 1485
Joined: Tue Jul 21, 2009 4:00 pm
Location: East Coast
Reputation: 1

Unread postAuthor: Gun Freak » Fri Oct 15, 2010 5:45 pm

I sharpened a piece of the chamber and punched some neoprene out then put it at the bottom of a section of the chamber pipe. Then I lubed it and put in the epoxy. It is curing right now so I'll take it out tomorrow. Should the epoxy be good enough to hold on the neoprene? It's Loctite 5 minute epoxy.
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Sponsored

Sponsor
 


Unread postAuthor: clemsonguy1125 » Fri Oct 15, 2010 5:54 pm

So you cast an epoxy piston, seems like way more work than nessacery, sudt use a keychain thats like a 1/4 inch thick
  • 0

User avatar
clemsonguy1125
Major General
Major General
 
Posts: 1485
Joined: Tue Jul 21, 2009 4:00 pm
Location: East Coast
Reputation: 1

Unread postAuthor: Gun Freak » Fri Oct 15, 2010 6:08 pm

I have another pengun on the way. I'll try a solid rubber piston in that one.
Pick the first one or the second one:
The schrader can be hidden or not. Either way, the front part of the pen would need to be removed in order to fire it.
Image
Image
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Unread postAuthor: Gun Freak » Sat Oct 16, 2010 11:04 am

I took the piston out of the mold today, it was tough but it came out. The rubber on the face came off. The epoxy was not enough to keep it on. A solid rubber piston is in order.
Image
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Unread postAuthor: ilovefire » Sat Oct 16, 2010 6:41 pm

what i did for my pen guns is i used contact adhesive to stick it to the piston and it seems to stay alright
  • 0

User avatar
ilovefire
Colonel
Colonel
 
Posts: 511
Joined: Sat May 22, 2010 6:48 am
Reputation: 0

Unread postAuthor: Crna Legija » Sat Oct 16, 2010 8:06 pm

use super glue or rubber cement that you get in tire repair kits to hold rubber down, epoxy just wont stick to rubber
  • 0

'' To alcohol... The cause of, and solution to, all of life's problems.”
--Homer Simpson

Add me on ps3: wannafuk, 8/11/11 cant wait
User avatar
Crna Legija
Major General
Major General
 
Posts: 2333
Joined: Sun Jul 20, 2008 5:14 am
Location: australia
Reputation: 0

Unread postAuthor: Gun Freak » Sun Oct 17, 2010 8:43 am

Are you sure super glue will hold it cause it's not servicable.
  • 0

OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
Gun Freak
Lieutenant General
Lieutenant General
 
Posts: 4969
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Country: United States (us)
Reputation: 11

Unread postAuthor: ilovefire » Sun Oct 17, 2010 8:06 pm

test it with a scrap bit of rubber and some wast epoxy and see if you think it is strong enough
  • 0

User avatar
ilovefire
Colonel
Colonel
 
Posts: 511
Joined: Sat May 22, 2010 6:48 am
Reputation: 0

Unread postAuthor: SpudBlaster15 » Sun Oct 17, 2010 9:36 pm

Cyanoacrylate adhesive will work fine. I've used it to bond sealing faces to pistons that are too small to accept a bolt and washer, and I have never had a failure, even at 400PSI in a T valve design.
  • 0

People should not be afraid of their governments. Governments should be afraid of their people.
User avatar
SpudBlaster15
Major General
Major General
 
Posts: 2385
Joined: Wed Oct 18, 2006 11:12 pm
Location: Canada
Country: Poland (pl)
Reputation: 3

Next

Return to Construction Materials/Ammo Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'