Special Ops Paintball: never ever EVER made a homemade law - Special Ops Paintball

Jump to content


  • (7 Pages)
  • +
  • « First
  • 3
  • 4
  • 5
  • 6
  • 7
  • You cannot start a new topic
  • You cannot reply to this topic

never ever EVER made a homemade law i could have died

#61 User is offline   Wimpy 

  • I make stuff up... don't listen.
  • PipPipPipPip
  • Group: Members
  • Posts: 970
  • Joined: 07-April 05
  • Gender:Male
  • Location:Charlottesvile VA
  • Brigade Name:Wimpy

Posted 17 April 2008 - 01:49 PM

View Postflorentine, on Apr 17 2008, 07:47 AM, said:

View PostWimpy, on Apr 17 2008, 10:42 AM, said:

So I DID read the first few pages of the thread, but then I had to comment. Was the expansion chamber PVC? Or was it Steel?

pvc, big mistake on my part


Ouch. Sorry for your accident bro. I must say that was a bad decision. I was worried it was steel in which case I was going to immediately get rid of my law. Glad you're okay.
0

#62 User is offline   Incognito 

  • Using Less Than 100 Paintballs A Day
  • PipPipPipPip
  • Group: Members
  • Posts: 808
  • Joined: 11-December 06
  • Gender:Male
  • Location:Hawaii

Posted 17 April 2008 - 05:00 PM

View Postthebostinian, on Apr 14 2008, 11:19 AM, said:

QFT. not only was this dangerous for florentine, but if it hadn't happened to him, i can guarantee it would've happened to one of the guys he built it for...and then, not only would there have been potentially a severe injury and/or fatality, but florentine would've been up to his neck in lawsuits.


Holy crud! You're right! Florentine was building that for my best friend (DeltaX) to carry! If Delta had used it and it would've blown up, I'd be short a best friend right now! I didn't realize how close that was...

~Quip~

EDIT: Misread previous post. If anyone saw that original comment, I apologize.

This post has been edited by Quip: 17 April 2008 - 05:02 PM

~Christian Paintballer~CPPA Member #3565~Stock Class Paintballer~Automaggot~My Feedback
Posted Image
The Family: VSC Phantom, PGP, Classic Automag, Autococker, Pumpcocker
U.S. Army Infantry: Because Someone Needs to Take Out the Trash
0

#63 User is offline   Florentine 

  • Group: Banned
  • PipPipPipPipPipPipPip
  • Group: Members
  • Posts: 6,356
  • Joined: 27-December 06
  • Gender:Male
  • Location:Pennsylvania

Posted 17 April 2008 - 05:05 PM

View PostQuip, on Apr 17 2008, 08:00 PM, said:

View Postthebostinian, on Apr 14 2008, 11:19 AM, said:

QFT. not only was this dangerous for florentine, but if it hadn't happened to him, i can guarantee it would've happened to one of the guys he built it for...and then, not only would there have been potentially a severe injury and/or fatality, but florentine would've been up to his neck in lawsuits.


Holy crud! You're right! Florentine was building that for my best friend (DeltaX) to carry! If Delta had used it and it would've blown up, I'd be short a best friend right now! I didn't realize how close that was...

~Quip~

EDIT: Misread previous post. If anyone saw that original comment, I apologize.

trust me, thats why i tested it alot before i let anybody else really shoot it.
Hey baby, wanna come over to myspace so i can twitter your yahoo till I google all over your facebook?
Feedback

Becc: "I'm not really a vegetarian, I eat some forms of sausage."
0

#64 User is offline   Mobles 

  • Better than Mack
  • PipPipPipPipPipPip
  • Group: Members
  • Posts: 4,921
  • Joined: 23-August 07
  • Gender:Male
  • Location:Tennessee/Alabama state line
  • Brigade Name:T-Freak

Posted 17 April 2008 - 05:09 PM

wow..Glad your ok! bet that hurt! :rolleyes:

EDIT: please dont kill yourself till you pay me the rest of my Money :P ..j/k

This post has been edited by T-Freak: 17 April 2008 - 05:10 PM

Life is short, get off your couch
[IMG-]http://i215.photobuc...eak/meeko-1.jpg[-/IMG]
Posted Image

0

#65 User is offline   Silent-7 

  • Christian Paintballer
  • PipPipPipPipPip
  • Group: Members
  • Posts: 1,088
  • Joined: 03-June 05
  • Gender:Male
  • Location:Highlands Ranch, CO
  • Brigade Name:Silent-7

Posted 17 April 2008 - 05:11 PM

If I was the first person to respond to this thread, I probably would have freaked out on you a little bit for lack of safety, etc. etc.
But since everyone else has pretty much taken care of that, I'll just say that I'm really sorry to hear you got hurt, but I'm glad that it wasn't any worse. It easily could have been. And since it sounds like you've learned your lesson, make sure you warn other people about what can happen if they try to cut corners when building one of these kinds of things!
Posted Image
0

#66 User is offline   Florentine 

  • Group: Banned
  • PipPipPipPipPipPipPip
  • Group: Members
  • Posts: 6,356
  • Joined: 27-December 06
  • Gender:Male
  • Location:Pennsylvania

Posted 17 April 2008 - 07:02 PM

View PostSilent-7, on Apr 17 2008, 08:11 PM, said:

make sure you warn other people about what can happen if they try to cut corners when building one of these kinds of things!

and thats why i made this thread. i thought i didn't have to use metal
Hey baby, wanna come over to myspace so i can twitter your yahoo till I google all over your facebook?
Feedback

Becc: "I'm not really a vegetarian, I eat some forms of sausage."
0

#67 User is offline   Blitzen 

  • DIY Specialist
  • PipPipPipPip
  • Group: Members
  • Posts: 762
  • Joined: 27-April 06
  • Gender:Male
  • Location:Middle Tennessee State University (TN)
  • Brigade Name:Blitzen

Posted 17 April 2008 - 08:53 PM

Been doing some math and this stuff isnt adding up...

P1*V1=P2*V2

So:
800 (PSI Output of a 12gram) * 5.56 (volume of 12gram)=X * 21.205 (volume of the airchamber).

800 * 5.56 = 198.05 PSI in the airchamber
21.205

What did you say the pipe pressure rating was? That math was using Boyle's Law, yet I am pretty sure that since Co2 can become a liquid, it sorta screws the math/equation up some (as well as temperature)

This post has been edited by Blitzen: 17 April 2008 - 08:57 PM

0

#68 User is offline   thebostinian 

  • SOFA Favorite Member Title 2009
  • PipPipPipPipPip
  • Group: Members
  • Posts: 1,268
  • Joined: 08-May 07
  • Gender:Male
  • Location:Grove City College or Burnt Hills, NY
  • Brigade Name:thebostinian

Posted 17 April 2008 - 09:23 PM

View PostBlitzen, on Apr 17 2008, 11:53 PM, said:

Been doing some math and this stuff isnt adding up...

P1*V1=P2*V2

So:
800 (PSI Output of a 12gram) * 5.56 (volume of 12gram)=X * 21.205 (volume of the airchamber).

800 * 5.56 = 198.05 PSI in the airchamber
21.205

What did you say the pipe pressure rating was? That math was using Boyle's Law, yet I am pretty sure that since Co2 can become a liquid, it sorta screws the math/equation up some (as well as temperature)

blitzen, i think your numbers are off...

"Yeah, but a thread that started out as borderline weird and creepy to begin with has now taken a left turn into 'Deliverance." - Violator
Don't try to pronounce the second "o". Instead, try realize the truth: there is no second "o"
0

#69 User is offline   Jackson 

  • Resident Tiberius Expert
  • PipPipPipPipPipPip
  • Group: Members
  • Posts: 2,947
  • Joined: 01-February 05
  • Gender:Male
  • Location:Pittsburgh, PA
  • Brigade Name:PvtDBJackson

Posted 17 April 2008 - 09:28 PM

View Postthebostinian, on Apr 18 2008, 12:23 AM, said:

View PostBlitzen, on Apr 17 2008, 11:53 PM, said:

Been doing some math and this stuff isnt adding up...

P1*V1=P2*V2

So:
800 (PSI Output of a 12gram) * 5.56 (volume of 12gram)=X * 21.205 (volume of the airchamber).

800 * 5.56 = 198.05 PSI in the airchamber
21.205

What did you say the pipe pressure rating was? That math was using Boyle's Law, yet I am pretty sure that since Co2 can become a liquid, it sorta screws the math/equation up some (as well as temperature)

blitzen, i think your numbers are off...

Yes. VERY off. Boyle's Law is for ideal gases. Which technically don't ever exist. Not really a problem, it approximates close enough. But you didn't factor in that CO2 is a liquid. Much much more dense than the gas form. It expands into a lot of gas from a small volume.

Like I said before, even if you think you know the math, you probably don't.

This post has been edited by Jackson: 17 April 2008 - 09:28 PM

0

#70 User is offline   Florentine 

  • Group: Banned
  • PipPipPipPipPipPipPip
  • Group: Members
  • Posts: 6,356
  • Joined: 27-December 06
  • Gender:Male
  • Location:Pennsylvania

Posted 18 April 2008 - 03:33 AM

well cab you give me the right size for using a 12 gram?
Hey baby, wanna come over to myspace so i can twitter your yahoo till I google all over your facebook?
Feedback

Becc: "I'm not really a vegetarian, I eat some forms of sausage."
0

#71 User is offline   Marauder_Pilot 

  • Thrilling Heroics
  • PipPipPipPipPipPip
  • Group: Members
  • Posts: 3,237
  • Joined: 10-May 06
  • Gender:Male
  • Location:Whitehorse, Yukon
  • Brigade Name:Marauder_Pilot

Posted 18 April 2008 - 06:10 AM

View PostJackson, on Apr 17 2008, 09:28 PM, said:

View Postthebostinian, on Apr 18 2008, 12:23 AM, said:

View PostBlitzen, on Apr 17 2008, 11:53 PM, said:

Been doing some math and this stuff isnt adding up...

P1*V1=P2*V2

So:
800 (PSI Output of a 12gram) * 5.56 (volume of 12gram)=X * 21.205 (volume of the airchamber).

800 * 5.56 = 198.05 PSI in the airchamber
21.205

What did you say the pipe pressure rating was? That math was using Boyle's Law, yet I am pretty sure that since Co2 can become a liquid, it sorta screws the math/equation up some (as well as temperature)

blitzen, i think your numbers are off...

Yes. VERY off. Boyle's Law is for ideal gases. Which technically don't ever exist. Not really a problem, it approximates close enough. But you didn't factor in that CO2 is a liquid. Much much more dense than the gas form. It expands into a lot of gas from a small volume.

Like I said before, even if you think you know the math, you probably don't.


Not to mention the fact that it probably wasn't the 12-gram itself, but the earlier use of a CO2 tank.
0

#72 User is offline   Silent-7 

  • Christian Paintballer
  • PipPipPipPipPip
  • Group: Members
  • Posts: 1,088
  • Joined: 03-June 05
  • Gender:Male
  • Location:Highlands Ranch, CO
  • Brigade Name:Silent-7

Posted 18 April 2008 - 12:38 PM

^Jackson's got it. If there was only gaseous CO2 at 800psi in the 12gram, then your numbers would be reasonable. They'd still be off since CO2 is very, very far from an ideal gas, but you'd be in the ballpark. However, the whole point of using CO2 in paintball guns is that liquid CO2 will go to gaseous CO2 if the pressure drops below 800psi or so. This is why a very basic paintball gun can run on close to 800psi for an extended period of time without regulating down from a higher pressure source.

In short, if there was enough liquid in the 12gram (I don't know how much is actually in there) the PVC chamber could theoretically have been at 800psi itself. I doubt that was the case, but you get the picture...
Posted Image
0

#73 User is offline   DeltaX 

  • ION Spec Ops Leader
  • PipPipPipPip
  • Group: Members
  • Posts: 953
  • Joined: 16-July 07
  • Gender:Male
  • Location:Carlisle, Pa
  • Brigade Name:DeltaX

Posted 18 April 2008 - 06:13 PM

Man Florentine. So glad your okay though. I'm glad thought this didnt happen till I was in a scenario and it blow up. I would be dead or very seriously injured.
0

#74 User is offline   mchainmail 

  • Sophomore Member
  • PipPipPip
  • Group: Members
  • Posts: 272
  • Joined: 19-July 06
  • Brigade Name:mchainmail

Posted 18 April 2008 - 08:06 PM

View PostBlitzen, on Apr 13 2008, 10:56 PM, said:

Umm...well no wonder it blew up. Did you do any research before you plugged all of this together? I believe you would have been okay if you had used steel piping, but there is no way a 1.5 diameter 12" long PVC pipe section is going to hold that much pressure.
You are a very lucky man


How much pressure is it really holding?


View PostBlitzen, on Apr 17 2008, 11:53 PM, said:

Been doing some math and this stuff isnt adding up...

P1*V1=P2*V2

So:
800 (PSI Output of a 12gram) * 5.56 (volume of 12gram)=X * 21.205 (volume of the airchamber).

800 * 5.56 = 198.05 PSI in the airchamber
21.205

What did you say the pipe pressure rating was? That math was using Boyle's Law, yet I am pretty sure that since Co2 can become a liquid, it sorta screws the math/equation up some (as well as temperature)


Instead of using Boyle's, let's use the ideal gas law.

We have a 1.5" by 12" pressure chamber.

V = (D/2)^2*pi*L
V = 21.206 cubic inches

Google says: 1 cubic inches = 16.387064 cubic centimeter
16.387*21.20 = 347.499 cubic centimeters

Google says: 1 cubic centimeter = 0.001 liter
.347 L of space in the expansion chamber

CO2's molecular mass is 44.01 g/mol
there are 12 grams of CO2 in a 12 gram.
12/44.01= .273 mol CO2

The ideal gas law:
PV=nRT
P*.347=.273*.0821*295.778 (assuming 73 degrees air temp.)
P= 19.1 atm

Google says: 1 atm = 14.6959488 pounds per square inch
19.1* 14.696 = 280.6 PSI


Therefore, we can see that the pressure in the pressure chamber was 280.6 PSI. However, the major issue at hand is not the pressure chamber, but rather the valve. Most valves are rated in the 100-150 PSI range.


What can we learn from this?

The pressure chamber needs to be larger. This entire fiasco could have been averted if the chamber was longer.

Working backwards, if we want the pressure in the chamber to be 100 psi, we would need a chamber of approximately 1 liter. This equals a minimum, safe pressure chamber size of:
2" X 20" or 1.5" X 34.5"


I will agree that it was foolish to use unregulated CO2. However, properly used, 12 grams are the BEST and SAFEST way of creating air cannons. They limit the available air to a SAFE pressure and do not have regulator creep or other negative affects.

I would also like to extend condolences to the poster and wish his safe return to health.

This post has been edited by mchainmail: 18 April 2008 - 08:07 PM

0

#75 User is offline   Marauder_Pilot 

  • Thrilling Heroics
  • PipPipPipPipPipPip
  • Group: Members
  • Posts: 3,237
  • Joined: 10-May 06
  • Gender:Male
  • Location:Whitehorse, Yukon
  • Brigade Name:Marauder_Pilot

Posted 18 April 2008 - 08:13 PM

I dunno, the whole issue could have been totally prevented by Florentine spending $15 on a blowout valve and a threaded tap tool. And you can't get any safer then a pressure chamber that is physically incapable of holding more then the popout valve's rating. You don't even *need* a reg for that setup, but I'd still never go without because it's a) a nice backup and :dodgy: Stops you from wasting gas as the popout expels anything extra.
0

Share this topic:


  • (7 Pages)
  • +
  • « First
  • 3
  • 4
  • 5
  • 6
  • 7
  • You cannot start a new topic
  • You cannot reply to this topic

2 User(s) are reading this topic
0 members, 2 guests, 0 anonymous users