Short question topic

A place for general potato gun questions and discussions.
User avatar
wyz2285
First Sergeant 2
First Sergeant 2
Austria
Posts: 2385
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Has thanked: 1 time
Been thanked: 3 times
Contact:

Wed Sep 14, 2016 10:13 am

If the barrel is way too short for the cylinder I can imagine it would improve accuracy, I used to have a shorter inner barrel inside a longer outer barrel and the accuracy was considerably worse than having a matching inner-outer barrel, possibly duo to the disturbulence.
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
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

Tue Sep 20, 2016 12:39 pm

wyz2285 wrote:disturbulence
awesome neologism :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
wyz2285
First Sergeant 2
First Sergeant 2
Austria
Posts: 2385
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Has thanked: 1 time
Been thanked: 3 times
Contact:

Tue Sep 20, 2016 2:43 pm

When you have to work with two semi similar language and neither is your mother language :lol:
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
Kensingt0n
Private
Private
Posts: 19
Joined: Thu Oct 29, 2015 6:02 am

Tue Sep 20, 2016 11:27 pm

On the topic of Co2 and pressures, I've been reading through a lot of patents on Google for Co2 pistols and it sparked the thoughts of if I was to build my own valve, it would need to withstand the pressure of unregged gas.
When the canister is pierced, it's only a tiny hole so this would reduce the flow and the pressure being applied to the homemade reg valve, correct?
I guess my question is what pressures will the valve need to withstand?
(To clarify, I'm reffering to the valve where the canister is screwed into to transfer the gas)
jimmy101
Sergeant Major
Sergeant Major
United States of America
Posts: 3197
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Has thanked: 5 times
Been thanked: 15 times
Contact:

Wed Sep 21, 2016 12:12 am

Nope. Flow only affects pressure if the flow continues. Once the flow stops the two sides of the opening will be at the same pressure. Everything in your setup has to handle whatever the pressure is after the CO2 cartridge is punctured. Simplest case is that the "reg valve" has to be able to withstand the full pressure of the CO2 cartridge.
Image
Kensingt0n
Private
Private
Posts: 19
Joined: Thu Oct 29, 2015 6:02 am

Wed Sep 21, 2016 3:48 am

That was my first assumption, thanks for clarifying that Jimmy.
Hopefully I'll come up with something with my lack of heavy tools, although it's a helluva lot of pressure in those canisters..
User avatar
cowscankill
Private 4
Private 4
United States of America
Posts: 73
Joined: Sun Apr 10, 2011 8:09 am

Mon Nov 14, 2016 7:23 pm

What's the deal with regulators?

This one has a gauge with 160 PSI:

And this one has a gauge with 200 PSI:

As far as I can find, that's the maximum output pressure it can regulate for output, right? So if I have a primary tank at 400 PSI, and I attach it to one of those regulators to throttle down to 100 PSI going into a secondary with a PVC piston valve, that should be fine...? I can't find a maximum input pressure on these things, which is what I want to know. If I happen to up my primary from 400 PSI to 1000 PSI, what's the likelihood of these things failing at the 100 PSI output?
"Make everything as simple as possible, but not simpler." - Albert Einstein
User avatar
wyz2285
First Sergeant 2
First Sergeant 2
Austria
Posts: 2385
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Has thanked: 1 time
Been thanked: 3 times
Contact:

Mon Nov 14, 2016 7:39 pm

There are for compressors, the intake is less than 200 PSI.
Inside there is a large, polymer/plastic/non metallic diaphragm which could break under excessive pressure.
I use some European made ones that takes 18 Bar input. I use 300-400 PSI with them.
Accidentally put 1200 PSI in once, didn't blow up but was only for a couple seconds. You won't be able to turn the pressure adjustment knob at 1000 PSI.
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
User avatar
cowscankill
Private 4
Private 4
United States of America
Posts: 73
Joined: Sun Apr 10, 2011 8:09 am

Mon Nov 14, 2016 8:03 pm

wyz2285 wrote: I use some European made ones
Ah yeah, I figured it had some sort of plastic diaphragm. Darn, was hoping to get a steal on Amazon nonetheless. Thanks for the response.
Also I wouldn't mind shipping in from other countries, but the last time I did I had to deal with BSP and that's a hassle for the time being so I guess I'll just keep looking for one on ebay or something.
"Make everything as simple as possible, but not simpler." - Albert Einstein
User avatar
wyz2285
First Sergeant 2
First Sergeant 2
Austria
Posts: 2385
Joined: Sat Mar 06, 2010 7:50 am
Location: Porto, Portugal
Has thanked: 1 time
Been thanked: 3 times
Contact:

Mon Nov 14, 2016 8:12 pm

I'd suggest stay away from eBay/general online stores and find a pneumatic shop that offers proper data sheet with detailed description, pressure ratings and quality control. Then it would be safer to push the input limite a bit higher.
CpTn_lAw wrote: :D "yay, me wanna make big multishot pnoob with 1000 psi foot pump compressor using diamond as main material. Do you think wet bread make good sealant? " :D
Doodmens
Private 3
Private 3
Posts: 53
Joined: Tue May 19, 2015 7:44 am

Sat Nov 19, 2016 3:59 pm

Has anyone made a pressure regulator themselves? I've designed one and I'm planning to machine it soon.
Image
Size: 2" to 4", depends on application
In and output pressure: probably 1500 psi to 300 psi.. I've yet to fully decide. I might make a few, anyone interested?
User avatar
Xamllew
Private 4
Private 4
Posts: 98
Joined: Sun Aug 21, 2016 11:00 pm
Location: Belgrade
Has thanked: 2 times
Been thanked: 4 times

Fri Nov 25, 2016 8:18 pm

Anyone got experience with co2 tire inflators?

I'm working on a muzzleloading ball valve airgun with a 2 cubic inch chamber, I was looking into getting one of those cheap co2 tire inflators because it seems like a convenient and portable way to fill my chamber to a high PSI. If I were shooting for 300-400psi per shot how many charges could I get from a cartridge?
User avatar
Gippeto
First Sergeant 3
First Sergeant 3
Venezuela
Posts: 2503
Joined: Sat Jan 19, 2008 10:14 am
Location: Soon to be socialist shit hole.
Has thanked: 2 times
Been thanked: 17 times

Donating Members

Fri Nov 25, 2016 8:31 pm

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Xamllew
Private 4
Private 4
Posts: 98
Joined: Sun Aug 21, 2016 11:00 pm
Location: Belgrade
Has thanked: 2 times
Been thanked: 4 times

Fri Nov 25, 2016 8:49 pm

Somewhere around 7-12 shots, not bad! Much appreciated.
User avatar
cowscankill
Private 4
Private 4
United States of America
Posts: 73
Joined: Sun Apr 10, 2011 8:09 am

Wed Nov 30, 2016 2:42 pm

How do these silencers work?
Image
https://www.amazon.com/Legris-0610-Sint ... ir+muffler

I'd be interested in making one for a 1" modified sprinkler valve that I am using to port a tee piston. So far the gun works very well but the sprinkler valve is really loud. Could I just put cotton or something into a stainless steel tea-ball hemisphere and mount that on the exhaust of my sprinkler valve? Alternatively, if this isn't easy to replicate, could I just build a typical gun silencer with baffles and screw that into my sprinkler valve?
"Make everything as simple as possible, but not simpler." - Albert Einstein
Post Reply