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 72 users online :: 5 registered, 0 hidden and 67 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

High pressure steel piston valved rifle in progress.

Built a pneumatic cannon? Then post it here! This section is for completed, finished cannons that you have built. Please include pictures and information.
Sponsored 
  • Author
    Message

Unread postAuthor: Major Collins » Sat Nov 21, 2009 4:15 am

yes it was and yeah i had a look at eBay there is a perfect one that i want but doesn't ship to Australia ... -.- sigh.
  • 0

User avatar
Major Collins
1st Lieutenant
1st Lieutenant
 
Posts: 264
Joined: Wed Nov 18, 2009 6:18 am
Location: Western Australia
Reputation: 1

Unread postAuthor: POLAND_SPUD » Sat Nov 21, 2009 6:41 am

probably there are cheaper suppliers...
I've noticed that sometimes you can pay almost 50% less for exactly the same product

here compare the price from my first link with this one (the difference is in fact more than 50% and the shipping costs twice as much :) )

I've been looking for pneumatic stuff, literally for days - and now I more less know where to buy cheap stuff

do the same and you should find better offers

inonickname is right, ebay is a good source of cheap pneumatic stuff but you've got to visit it regularly to find the best deals... sometimes I buy stuff I don't need at that moment (but which is useful) just because it's a good bargain
  • 0

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: absinthe » Sat Nov 21, 2009 8:07 am

i have some 1/2" QEV's from bellpro (i bought 3) i wouldnt even consider using one as the main valve the ports are tiny,, i might use it as a pilot actuator valve though
  • 0


absinthe
Specialist
Specialist
 
Posts: 50
Joined: Wed Aug 12, 2009 7:15 am
Reputation: 0

Unread postAuthor: inonickname » Sat Nov 21, 2009 8:19 am

I'm considering modifying my 1/2" bellpro QEV. I know I can get at least twice as much gas through if i make a new seat/port and drill out the chamber and pilot ports.
  • 0

PimpAssasinG wrote:no im strong but you are a fat gay mother sucker that gets raped by black man for fun
User avatar
inonickname
Lieutenant General
Lieutenant General
 
Posts: 2606
Joined: Sun Dec 07, 2008 3:27 am
Reputation: 0

Unread postAuthor: Major Collins » Sat Nov 21, 2009 8:24 am

i cant find the price of stuff on that site lol hrmm how much is this? http://www.pneumatig.eu/quick-exhaust-v ... anguage=en
its is beautiful and i wouldn't mind having a smaller qev you can make a stock around it easier ;)
  • 0

User avatar
Major Collins
1st Lieutenant
1st Lieutenant
 
Posts: 264
Joined: Wed Nov 18, 2009 6:18 am
Location: Western Australia
Reputation: 1

Unread postAuthor: spudtyrrant » Sat Nov 21, 2009 12:54 pm

jhalek90 wrote: more lik.... S.S.R lol... jk
just call it the U.S.S.R.(ultimate small steel rifle) for good measure lol :lol:
  • 0

I ♥ ♣'in baby seals
User avatar
spudtyrrant
Colonel
Colonel
 
Posts: 550
Joined: Fri Jan 02, 2009 6:10 pm
Reputation: 0

Unread postAuthor: D_Hall » Sat Nov 21, 2009 1:04 pm

Except that it doesn't appear to be a rifle.
  • 0

Simulation geek (GGDT / HGDT) and designer of Vera.
User avatar
D_Hall
Donating Member
Donating Member
 
Posts: 1759
Joined: Thu Feb 07, 2008 7:37 pm
Location: SoCal
Reputation: 6

Sponsored

Sponsor
 


Unread postAuthor: POLAND_SPUD » Sat Nov 21, 2009 1:18 pm

how much is this?

they are 25.24$

while the one from this site is for 16.16$

both prices excluding tax

now do you get it ? they are exactly the same... one site has better pics but their products cost 50% more...

EDIT

ohh have a look here as well... they are for 12,11$ excl. tax

now you see...? compare 12$ to 24$ - you can pay 100% more for the same product

they are all polish shops.. some of them ship abroad but shipping would cost you too much... I've posted that just to show you that:

A there can be a huge difference in price between different suppliers

B even in Poland (which might be considered to be a 3rd world country by some of the guys here :) ) there are lots of places where you can buy QEVs... so probably there are good shops in AUS but you haven't found them yet
  • 0

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: jhalek90 » Sat Nov 21, 2009 2:50 pm

Major Collins wrote:wow that is a very small chamber and you say you can fit 150 psi :o my god thats fabulous .c to b ? huh lol well my sealing gasket doesn't seal up against the barrel surface part ...

look for my post in the link below : D

http://www.spudfiles.com/forums/self-cl ... rt,30.html


Im goin to put alot more than 150 psi in there... lol it shoudl be fine at 500 psi :-)
Good lick with the piston!!
make sure that the sealing faces, are perfectly flat...

Alright.... s0.. here we are again... the 1200 fps question...

If my daisy air rifle can hit 1600-1800 fps with a pellet.... why do you think it is impossible for me with a larger valve.... and larger chamber?
I know they use higher pressures... but still. it is not impossible.

So, unless you have more proof that i am wrong, than i do proof that im right, please shut up with the "That is impossible."

My chronograph is acurate, to a degree, so i took the lowest of the range of error. which was 1190 give or take a few fps.


The only way i will ever know if my chronograph is way off, is when i get the gun tested by a real chronograph. Which i am trying to do sometime soon. So, untill then.... ill shut up about the FPS.

When i get it tested for real. I will let you all know if i was right or wrong.
Thank you.
  • 0

User avatar
jhalek90
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 498
Joined: Fri Aug 14, 2009 5:37 pm
Reputation: 0

Unread postAuthor: Ragnarok » Sat Nov 21, 2009 3:33 pm

jhalek90 wrote:So, unless you have more proof that I am wrong, than I do proof that I'm right, please shut up with the "That is impossible."

Thanks for the offer.

If my daisy air rifle can hit 1600-1800 fps with a pellet.... why do you think it is impossible for me with a larger valve.... and larger chamber?
I know they use higher pressures... but still. It is not impossible.

It is impossible, because you're misunderstanding the importance of that pressure.

It's a fact of physics that no pressure based cannon can shoot faster than the speed of sound in its propellant. It's not physically possible - the speed of sound is the limit on how fast the propellant can expand, so it's obvious you can't shoot faster.

So, while things can shoot supersonic in air, they can only do so because their propellants have a higher speed of sound. (The gas is either hotter or lower molar mass.)

In air rifles, they can shoot supersonic because of adiabatic heating of their air.
In a springer, this comes about because of the compression of the air in the "power plant".
In any "pneumatic", be it PCP or CO2, then a supersonic shot comes about because of the compression of any air in the "dead volume" between valve and projectile.

Heating this dead volume sufficiently for even a marginally supersonic shot takes extreme pressures. Thousands of psi, not hundreds - and you don't have that pressure on tap.

Now, I doubt you have a 1600 fps air rifle. Yes, some things claim to get pellets that fast, but it's mostly marketing BS.
If something can get a pellet that fast, it will will almost certainly be a springer, because those only WORK because of the extreme heating (and thus high SOS) of their gas.

Either way, comparing springer velocities to PCP velocities is pretty moot.

~~~~~

If you want more than that, let me put it this way. Almost every claim of supersonic performance from a pneumatic on this forum has either never been backed up with evidence that it's true, or has been proven outright false.

As per Russel's teapot, the onus is on you to provide the proof, not on us to disprove you.

Until you have reliable evidence that you actually achieved that velocity, it is perfectly reasonable for us to argue against your claim, simply based on the reliability of previous claims of that velocity.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: jrrdw » Sat Nov 21, 2009 3:37 pm

Most Daisy's get 795 fps not 1700 to 1800.
  • 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: Major Collins » Sat Nov 21, 2009 9:30 pm

lol i see what your saying about the prices Poland Spud , but why are the sites in a language i cant understand lol :/ thats like trying to describe something to a blind person XD i need someone in Australia to show me where i can get them .. hrmmm.. anyone ? lol :D
  • 0

User avatar
Major Collins
1st Lieutenant
1st Lieutenant
 
Posts: 264
Joined: Wed Nov 18, 2009 6:18 am
Location: Western Australia
Reputation: 1

Unread postAuthor: POLAND_SPUD » Sun Nov 22, 2009 12:18 am

you could convert the prices by using google... all you've got to do is to type something like '20PLN -> USD' and it will convert the prices to USD for you... actually you don't have to do it but that's what I did

it would be the best if someone already knew that... but you can find the best shops yourself by using google that's how I found the best suppliers
and as I said earlier it literally took me days
  • 0

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: D_Hall » Sun Nov 22, 2009 12:23 am

jhalek90 wrote:My chronograph is acurate, to a degree, so i took the lowest of the range of error. which was 1190 give or take a few fps.


The only way i will ever know if my chronograph is way off, is when i get the gun tested by a real chronograph. Which i am trying to do sometime soon. So, untill then.... ill shut up about the FPS.


I'm curious....

If you've never tested your chonograph against a known system, how can you state that it's "accurate, to a degree?"
  • 0

Simulation geek (GGDT / HGDT) and designer of Vera.
User avatar
D_Hall
Donating Member
Donating Member
 
Posts: 1759
Joined: Thu Feb 07, 2008 7:37 pm
Location: SoCal
Reputation: 6

Unread postAuthor: spudtyrrant » Sun Nov 22, 2009 12:24 am

jhalek90 wrote: If my daisy air rifle can hit 1600-1800 fps with a pellet.... why do you think it is impossible for me with a larger valve.... and larger chamber?
I'm sorry but even the most powerful advertised airguns in the world only claim to shoot 1600fps(this is with super light, lead free pellets, and they are definitely not daisy's), trust us their are many cannons that have come before yours that were higher quality, use more pressure, and shoot faster than yours, and their builders haven't made the un-informed claims your making. honestly this cannon couldn't get over SOS with .25" pellets let alone 1" bouncy balls, any belief to the contrary is just flat wrong :roll:
  • 0

I ♥ ♣'in baby seals
User avatar
spudtyrrant
Colonel
Colonel
 
Posts: 550
Joined: Fri Jan 02, 2009 6:10 pm
Reputation: 0

PreviousNext

Return to Pneumatic Cannon Database

Who is online

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

Reputation System ©'