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

In total there are 40 users online :: 3 registered, 0 hidden and 37 guests

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

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

The Team
Global Moderators
global_moderators.png CS

Taking the pengun to the next level

A place to ask general spud cannon related questions.
  • Author

Taking the pengun to the next level

Unread postAuthor: inonickname » Tue Feb 03, 2009 3:47 am

Well after a spree of pen gun's and JSR's latest full auto works, I came up with this idea. It was inspired by the piston used in his gun and finding some thick alum. alloy pipe that a syringe sleeved perfectly in.

It has some design flaws at the moment, these being:

-Multiple holes in chamber.

-Tap and Die sets required for threaded barrel plug/spark plug. (I have a tap and die, speaking in general...)

-Schrader valves limit the mix capabilities.

-Epoxy plug for the rear schrader, should hold but would be risky without substantial tests. In theory it would hold as it only contains the pressure between it and the syringe, with a bit more as the piston is forced back during combustion.

-Limited mix capacity to offer safety margin for handheld firing.

-Use of stronger materials required.

-Difficulty in building the barrel plug. It may have to be permanent, making purging difficult.

Any thoughts/suggestions/weigh ins?
  • 0

zz pengun hybrid.PNG
zz pengun hybrid.PNG (10.82 KiB) Viewed 666 times
PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
Lieutenant General
Lieutenant General
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Unread postAuthor: daccel » Tue Feb 03, 2009 10:15 am

Well, it follows the same design, albeit with a coaxial layout, as other piston hybrids that work, so it should too.

To address the problem of weakening the chamber wall by having the two holes in it, perhaps you could fill via the barrel. Thread the muzzle or possibly a quick connect larger than the barrel ID. Then set the piston pressure to your fuel pressure and fill. Reset piston pressure to air pressure and fill. Reset piston pressure to desired pressure higher than mix pressure.

Or if you have an external meter, just have the piston pressure at zero, then raise it to final pressure before disconnecting the fueling line.

I would also definitely look at reinforcing that epoxy plug with screws, especially with the force of the piston coming back on it. If you made it with o-rings, and not actually fixed to the pipe, but held with screws behind it, you could remove it to adjust the spark gap or replace the piston.
  • 0

User avatar
Donating Member
Donating Member
Posts: 238
Joined: Thu Oct 11, 2007 9:51 pm
Location: BC, Canada
Reputation: 0

Unread postAuthor: psycix » Tue Feb 03, 2009 11:33 am

I dont feel much for threading the schrader and spark gap into the chamber wall like that. Maybe use T-pieces (or one cross) for that.
How do you plan to meter fuel?
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
Donating Member
Donating Member
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Tue Feb 03, 2009 2:42 pm

How about an extended version of this hybrid cartridge idea?

Not very practical way of sealing the projectile for lots of shots though.
  • 0

User avatar
Donating Member
Donating Member
Posts: 25044
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 131

Unread postAuthor: ALIHISGREAT » Tue Feb 03, 2009 3:27 pm

you could fill though the barrel by having a low PSI bumper behind the piston ... then increase the pressure behind the piston after fuelling... this would however be inconsistent...
  • 0

<a href="http://www.bungie.net/stats/halo3/default.aspx?player=ALI H IS GREAT"><img src="http://www.bungie.net/card/halo3/ALI H IS GREAT.ashx"></a>
User avatar
Major General
Major General
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Return to General Spud Cannon Related

Who is online

Registered users: Bing [Bot], Exabot [Bot], Google [Bot]

Reputation System ©'