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 65 users online :: 5 registered, 0 hidden and 60 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

Gas gun loading on a spudgun?

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

Gas gun loading on a spudgun?

Unread postAuthor: noob of noobs » Wed Aug 13, 2008 12:10 am

Okay, so due to new new parental restrictions involving the power of my work, I'm going to try to focus more on a higher rate of fire. So I'm going to try to build an automatic paintball gun.

The valve will be similar to the one in this thread: http://www.spudfiles.com/forums/semi-auto-piston-under-constant-air-flow-t15627.html The valve and airsource though isn't what I'm worried about.

The reloading mechanism is what I'm in question about. After looking at gas guns ( http://science.howstuffworks.com/machine-gun7.htm ) I was wondering if you could apply similar technology to a paintball gun. Bassicaly, the difference would be that instead of pushing the gun's bolt back, the piston would push back a hopper so that one paintball could fall into a hole in the barrel. The hopper would then be pushed back away from the hole by a spring.
The picture should explain things a bit more lucidly...

So what do you think? All comments are welcome. :D
  • 0

Attachments
Gasgun.JPG
Behold, the diagram
Gasgun.JPG (27.54 KiB) Viewed 459 times
User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

Unread postAuthor: trollhameran » Wed Aug 13, 2008 1:22 am

The picture doesn't really show how it fires to clearly, but the loading looks good, should work, perhaps I can suggest using a larger opening than you need for the ammo to fall into because then it will be easier for the ammo to drop in while the whole thing is moving, which will allow a higher rate of fire without the ammo getting jammed.
  • 0

User avatar
trollhameran
Colonel
Colonel
 
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm
Reputation: 0

Unread postAuthor: POLAND_SPUD » Wed Aug 13, 2008 2:18 am

I had a similar idea sometime ago... the only difference is that I am planing to use an air cylinder to do the job...

EDIT
Pics added..... (sorry for using MSPaint :wink: )

It's almost as simple as it can be.
The design requires a single acting air cylinder and a 3 way valve. The idea is that the 3 way valve fills the gun and the air cylinder (as they are joined toghether).

The air cylinder pushes the bolt forward loading new ammo and closing the breach.
When the 3 way valve pilots the gun the spring inside an air cylinder pulls the bolt back and new ammo falls from the hopper.

When the trigger is depresed (the 3 way valve switches to filling) the whole cycle repeats



Your design is very unlikely to work properly. People had serious problems with simple blowback bolts.

In your design you want air to move the whole hopper.
The hopper (+ ammo) is going to be very heavy when compared with a design where there is just a bolt to be moved. Even if it cycled properly there would be about 0.5 kg of plastic and ammo moving forward and backward at the same rate as your planed ROF and that isn't going to improve accuracy

I think you should read JSR's thread on his blowback gun (on failure of the design :wink: ) Then you'd better understand why your design is not going to work
  • 0

Attachments
bez tytułu.GIF
bez tytułu.GIF (9.58 KiB) Viewed 431 times
bez tytułu1.GIF
bez tytułu1.GIF (9.59 KiB) Viewed 431 times
Last edited by POLAND_SPUD on Wed Aug 13, 2008 3:14 am, edited 1 time in total.
Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: trollhameran » Wed Aug 13, 2008 3:12 am

Thats a very clever design Poland, I like it.
  • 0

User avatar
trollhameran
Colonel
Colonel
 
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Wed Aug 13, 2008 4:53 am

Bleeding air from the barrel to cycle the action will not work in a 150psi spudgun. Remember that assault rifles that use this system usually generate in excess of 40,000psi of pressure that provides the impetus for the cycling to happen.

Recently I took apart my FX Monsoon semi-auto air rifle:

Image

What it does is use the muzzle blast within the suppressor tube to push back a piston around the barrel. Again though, below 1500 psi it will not cycle. What you want for lower pressures is either a blow-forward bolt, or using direct blowback, have a browse through the forum using the search function ;)
  • 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

Unread postAuthor: Leonard » Wed Aug 13, 2008 4:48 pm

Another quick little thing i want to add. Moving the whole magazine each shot will result in terrible accuracy (gun shaking) and the cylinder that will contain the air that will push the spring is dead space considering you could go without it.
  • 0

User avatar
Leonard
Sergeant
Sergeant
 
Posts: 93
Joined: Fri Feb 08, 2008 1:38 am
Reputation: 0

Unread postAuthor: noob of noobs » Wed Aug 13, 2008 8:05 pm

@ ALL: Blech, thanks. I'm not very knowledgable in firearms and such, and just thought this might work here. Well, back to the drawing board...
Thanks for your time.
  • 0

User avatar
noob of noobs
Captain
Captain
 
Posts: 320
Joined: Tue Jun 12, 2007 8:04 pm
Location: Illinois, Skokie
Reputation: 0

Sponsored

Sponsor
 


Return to General Spud Cannon Related

Who is online

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

Reputation System ©'