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 73 users online :: 4 registered, 0 hidden and 69 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

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

Possibly stupid, possibly brilliant idea

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

Possibly stupid, possibly brilliant idea

Unread postAuthor: PVC Arsenal 17 » Wed Jan 02, 2008 7:28 pm

Most likely stupid. It was an idea had while falling asleep last night.

Anyway, I can't explain it much better than the picture does.

There is a tube, and inside is a check valve type of thing that moves back and forth like a piston. Pressure is applied from behind it (check valve is configured so that it's closed from behind) and this piston moves forward. It continues to do so until the "flapper" is pushed up against the barrel, at which point (if I'm not completely missing something, which I most likely am) it opens and all the air from behind the check valve is free to now move out the barrel.

I'm not sure whether the pressure pushing on the piston will be enough to crack open the seal when it pushes against the barrel. Say 50 pounds of pressure sit behind the piston. Would it take more than 50 pounds than to crack the seal, or less because it's a smaller area? I'm having trouble trying to understand what would happen.

I'm sure that if it did work, it would have horrible performance, however it would be fairly easy to make. (PVC extension couplings and a swing check valve) That's the only reason I bothered posting it.
  • 0

Attachments
fa.PNG
fa.PNG (11.35 KiB) Viewed 698 times
Last edited by PVC Arsenal 17 on Wed Jan 02, 2008 7:38 pm, edited 1 time in total.

PVC Arsenal 17
Major General
Major General
 
Posts: 1762
Joined: Mon Mar 27, 2006 4:18 pm
Location: United States
Reputation: 1

Unread postAuthor: jrrdw » Wed Jan 02, 2008 7:37 pm

Your asking to much of your design.
  • 0

When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6538
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: MrCrowley » Wed Jan 02, 2008 7:40 pm

Poor flow, even if it did somehow work.

What's the advantage over a normal piston?
  • 0

User avatar
MrCrowley
Moderator
Moderator
 
Posts: 10207
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Country: New Zealand (nz)
Reputation: 4

Unread postAuthor: PVC Arsenal 17 » Wed Jan 02, 2008 7:45 pm

MrCrowley wrote:Poor flow, even if it did somehow work.

What's the advantage over a normal piston?


Absolutely nothing! I was just trying to keep my mind busy. :lol:
  • 0


PVC Arsenal 17
Major General
Major General
 
Posts: 1762
Joined: Mon Mar 27, 2006 4:18 pm
Location: United States
Reputation: 1

Unread postAuthor: King_TaTer » Wed Jan 02, 2008 7:49 pm

I think its a pretty respectable idea , its almost like a combination of a piston, and diaphragm valve plus a burst disk. eh? as for your questions this mostly depends on what kind of disk/flap/diphram your going to use. as for ease of funtion and less complication i would recommend somthing that shatters or is disposable like alu. foil. You were saying above about a "flapper" of some sort. for one it would have to be rigid enough to not be suctioned against the barrel. also youd have to figure out a way to cock it or hold it in place till the pressure rises high enough to shoot it.

Good idea overall man , keep thinking about it and try designing a simple prototype. cheers! :P
  • 0

User avatar
King_TaTer
1st Lieutenant
1st Lieutenant
 
Posts: 265
Joined: Fri Nov 17, 2006 6:14 pm
Reputation: 0

Unread postAuthor: MrCrowley » Wed Jan 02, 2008 7:56 pm

PVC Arsenal 17 wrote:
MrCrowley wrote:Poor flow, even if it did somehow work.

What's the advantage over a normal piston?


Absolutely nothing! I was just trying to keep my mind busy. :lol:


Fair enough, as long as you keep your mind going over things like this.

One day you might get lucky, like how JSR gets lucky every morning he wakes up and posts another way to achieve semi-auto. :D
  • 0

User avatar
MrCrowley
Moderator
Moderator
 
Posts: 10207
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Country: New Zealand (nz)
Reputation: 4

Unread postAuthor: VH_man » Wed Jan 02, 2008 8:19 pm

thats actually a good idea......... check valves are realy just hammer valves.........

i think this might give you a cool "pulsed" automatic thing if you put a spring to make it return to the back and gave it a low enough flow. actually, i might try this.......
  • 0

User avatar
VH_man
Major General
Major General
 
Posts: 1827
Joined: Sat Dec 09, 2006 6:00 pm
Location: New Hampshire
Reputation: 1

Sponsored

Sponsor
 


Unread postAuthor: Skywalker » Wed Jan 02, 2008 10:34 pm

Yep, Nobel Prize winner Linus Pauling said "In order to have good ideas, you must first have lots of ideas." I like brainstorming. Ideas start to mutate and breed and first thing you know, something decent comes of it. Maybe even a winner.

I think the problem is that you'd need that piston to take off down the cylinder all of a sudden in order to knock the door open, otherwise it would suction the door to the barrel like a normal barrel sealer. But if you have something to release the piston once it's already under pressure, you've gone and made it something that could be a valve all by itself.
  • 0

User avatar
Skywalker
Sergeant Major
Sergeant Major
 
Posts: 177
Joined: Sun Aug 05, 2007 7:22 pm
Reputation: 0

Unread postAuthor: mark.f » Wed Jan 02, 2008 10:55 pm

I have a few suggestions:

1.) Make the barrel eccentric to the chamber. You could probably use a solid (socket weld) plug, with a hole the OD of the pipe you're using drilled in the plug.

2.) make the diaphragm supported by a solid disk, so it doesn't flex and maintain the seal on the back of the barrel.
  • 0

User avatar
mark.f
Donating Member
Donating Member
 
Posts: 3464
Joined: Sat May 06, 2006 11:18 am
Country: United States (us)
Reputation: 21

Unread postAuthor: SPG » Thu Jan 03, 2008 6:22 am

Problem: The air pressure on your flap is pushing equally all over it. The flap hangs vertical and your barrel end is also vertical. The pressure will just seal the flap onto the barrel (no suction involved).

The way round it would be to increase the size of the piston face to larger than that of the check valve plate, and try cutting the barrel end to 45° (with the longer side at the top in your drawing) . This means the force on the piston is larger than that on the check valve so it should open. and the cut should help with the flow.
  • 0

User avatar
SPG
Major
Major
 
Posts: 364
Joined: Thu Feb 09, 2006 11:55 am
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Thu Jan 03, 2008 6:30 am

MrCrowley wrote:One day you might get lucky, like how JSR gets lucky every morning he wakes up and posts another way to achieve semi-auto. :D


It's a bit like evolution in nature - if there's a problem, throw as many different potential solutions at it as possible, one of them is bound to work :)
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Return to General Spud Cannon Related

Who is online

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

Reputation System ©'