GB Semi

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.
SEAKING9006
Corporal 3
Corporal 3
Posts: 734
Joined: Mon Jun 23, 2008 3:20 pm
Location: Texas

Wed Mar 18, 2009 12:26 pm

One; Do not bump old topics with just a question to the builder.
Two; It won't because the pressure is pushing the other way. It wants to go LEFT.
Completed projects:
CA1 SMSS Basic Inline
CA3 PDAB Airburst Cannon

Current Project: Bolt action rifle (25x140mm + 1in shot)
clide
Corporal 3
Corporal 3
Posts: 784
Joined: Sun Mar 06, 2005 3:06 am
Location: Oklahoma, USA
Been thanked: 1 time

Donating Members

Sat Mar 21, 2009 10:22 pm

To clarify what Seaking said. The pressure is pushing it to the left because the left side of the piston is slightly larger than the right.

There is also a physical stop (The threaded adapter by the middle piston) that stops momentum from carrying the piston too far forward.
<a href="http://gbcannon.com" target="_blank"><img src="http://gbcannon.com/pics/misc/pixel.png" border="0"></a>latest update - debut of the cardapult
User avatar
mattyzip77
Sergeant 3
Sergeant 3
United States of America
Posts: 1249
Joined: Tue Jun 28, 2011 12:22 pm
Location: Taxachusetts

Donating Members

Wed Aug 29, 2012 8:46 am

I know this is a old thread but is clide still around?? This gun and valve is freakin unreal!!!!!! :shock: :shock: :shock:
Go Bruins!!!!
User avatar
POLAND_SPUD
Captain
Captain
Posts: 5402
Joined: Sat Oct 13, 2007 4:43 pm
Been thanked: 1 time

Wed Aug 29, 2012 9:25 am

nothing you couldn't achieve with a 3 way + QEV + air cylinder combo

the biggest problem is that you need lots of compressed air - if your chamber is for example 1 litre @ 10 bar you need 10 litres of air at atmosferic pressure

now if you want just 3 RPS rate of fire then you need 30 litres of air... to make matters worse your gun and all of its parts have to be able to deliver that 30 litres of air in one second... so forget about using small and cheap DCVs as they might constrict the flow too much
Children are the future

unless we stop them now
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26203
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 569 times
Been thanked: 343 times

Donating Members

Wed Aug 29, 2012 9:36 am

POLAND, this is why regulated HPA tanks exist ;)
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
POLAND_SPUD
Captain
Captain
Posts: 5402
Joined: Sat Oct 13, 2007 4:43 pm
Been thanked: 1 time

Wed Aug 29, 2012 11:08 am

I am not sure what you're saying... I mentioned litres of air at atmospheric pressure just to show how much flow each part has to handle

I doubt the reg on your setup could provide enough flow for a largebore fullauto gun operating at let say 5 RPS
Children are the future

unless we stop them now
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26203
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 569 times
Been thanked: 343 times

Donating Members

Wed Aug 29, 2012 4:09 pm

There are high flow regulators... or you could drive yourself crazy by using a pop-off to refill the chamber and trying to balance the firing cycle :)
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
velocity3x
Corporal 4
Corporal 4
Posts: 828
Joined: Fri Jun 05, 2009 3:09 pm
Location: Yuma, Arizona
Contact:

Wed Aug 29, 2012 5:11 pm

I use one these .... It provides more than enough volume for 60 rpm's at 60 bar. It has a max pressure of about 408 bar.

http://www.scottgrossstore.com/servlet/ ... igh/Detail
User avatar
POLAND_SPUD
Captain
Captain
Posts: 5402
Joined: Sat Oct 13, 2007 4:43 pm
Been thanked: 1 time

Wed Aug 29, 2012 6:13 pm

sure but that's 60 rpm per 60 seconds in a minute right?? now try to get 5 RPS and you're fcked

not to mention that your gun isn't really self contained or something you can carry on your back
Children are the future

unless we stop them now
User avatar
velocity3x
Corporal 4
Corporal 4
Posts: 828
Joined: Fri Jun 05, 2009 3:09 pm
Location: Yuma, Arizona
Contact:

Wed Aug 29, 2012 7:12 pm

POLAND_SPUD wrote:sure but that's 60 rpm per 60 seconds in a minute right?? now try to get 5 RPS and you're fcked

My bad....I read that as 5 rpm rather than 5rps.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26203
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 569 times
Been thanked: 343 times

Donating Members

Thu Aug 30, 2012 12:09 am

I think velocity3x can confirm that if you're making an HPA auto with a relatively big bore, 1rps is more than enough to devastate pretty much anything...
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
POLAND_SPUD
Captain
Captain
Posts: 5402
Joined: Sat Oct 13, 2007 4:43 pm
Been thanked: 1 time

Thu Aug 30, 2012 4:00 am

maybe it is but he knew that flow will be a problem and he took special care and ordered parts that offer good flow just to get it to work at 1 RPS

so the point is -> fullauto guns require a lot of flow and that has to be taken into consideration when designing a gun
Children are the future

unless we stop them now
User avatar
ramses
Staff Sergeant 2
Staff Sergeant 2
United States of America
Posts: 1679
Joined: Thu May 29, 2008 6:50 pm

Thu Aug 30, 2012 9:47 am

POLAND_SPUD wrote: so the point is -> fullauto guns require a lot of flow and that has to be taken into consideration when designing a gun
And auto hybrids get 760% more flow per flow!
POLAND_SPUD wrote:even if there was no link I'd know it's a bot because of female name :D
User avatar
al-xg
Corporal 2
Corporal 2
Great Britain
Posts: 643
Joined: Fri Jan 19, 2007 12:29 pm

Thu Aug 30, 2012 10:36 am

so the point is -> fullauto guns require a lot of flow and that has to be taken into consideration when designing a gun
Yep, one of the biggest issues I encountered when trying to get my 14mm full auto prototypes to function at a decent power level and rate of fire.
Post Reply