constant flow full auto :)

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
User avatar
POLAND_SPUD
Captain
Captain
Posts: 5402
Joined: Sat Oct 13, 2007 4:43 pm
Been thanked: 1 time

Sat Nov 07, 2009 1:54 pm

I don't think a vehicle mounted autocannon would be consistent with keeping a low profile
well but that would be cool wouldn't it ?? :D

first of all, you would need quite a lot of compressed air for this project... a car engine can provide enough HPs to power even a large air compressor

and I remember that you've mentioned that you don't have enough space to test larger guns... so with an on board air compressor you could drive to some remote part of XXXXXXXXXXXXX and test them there

what is more, you could mod the compressor to acheive higher pressures with it
Children are the future

unless we stop them now
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 321 times

Donating Members

Sun Nov 08, 2009 10:08 am

The coolness factor would certainly make it worthwhile :)

I was also considering buying a slightly bigger paintball bottle, feeding this thing 450 psi at a low rate should be a viable proposition because according to the markings on the valve it can be advusted to pop from 0 to 3 bar, 45 psi isn't much so large flow and bore are important.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Procyon
Private 2
Private 2
Posts: 29
Joined: Fri Oct 16, 2009 3:45 pm

Tue Nov 10, 2009 6:40 pm

I like it.

What's the rating on your valve? When the 200 pops on my RPG everyone around jumps. I can definitely see good potential for a strong shooter with a 200 psi valve going off with 250 behind it. Nice thinking. I'll be joining those giving it a try. I would think you could also control rate of fire as well by adjusting input pressure. Great idea!
User avatar
Solar
Corporal
Corporal
United States of America
Posts: 545
Joined: Tue May 17, 2005 11:53 pm
Has thanked: 1 time
Been thanked: 17 times

Tue Nov 10, 2009 7:34 pm

Polyconn will make ones for higher psis as well. They have larger port openings as well.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 321 times

Donating Members

Wed Nov 11, 2009 1:28 am

Procyon wrote:What's the rating on your valve? When the 200 pops on my RPG everyone around jumps. I can definitely see good potential for a strong shooter with a 200 psi valve going off with 250 behind it. Nice thinking. I'll be joining those giving it a try. I would think you could also control rate of fire as well by adjusting input pressure. Great idea!
The body has PN16 stamped on it, so it will happily take 235 psi. The pop-off rating however is marked as 0-3 BAR, so that's around 45 psi maximum pop-off pressure.

The thing about using standard pop-offs it that they are not optimised for "full auto" operation, I determined that a succesful valve used in this manner needs the following criteria:
1) The piston seat must be significantly bigger than the outlet to the barrel, to ensure that the piston chamber fills with pressure faster than it can empty and the piston has time to actually pop

2) The piston must be significantly wider than the piston seat, in order for there to be enough area for the pressure to act on and overcome the spring strength.
The 1" valve is currently being modded to satisfy these conditions. I had ended up making my own pop-off with the above parameters in mind, take a look at version 1 and version 2

Hook it up to a barrel and magazine and it works :D

[youtube][/youtube]
Polyconn will make ones for higher psis as well. They have larger port openings as well.
I had made an HPA version but given my limited construction facilities the porting is relatively tiny.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Post Reply