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 52 users online :: 5 registered, 0 hidden and 47 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

5 gallon water bottle chamber

Post about things you have launched or thought about launching. Also post about various materials used for building cannons. No posts about explosive projectiles!
Sponsored 
  • Author
    Message

5 gallon water bottle chamber

Unread postAuthor: Eddbot » Thu Dec 13, 2007 2:01 am

ok, i was in french class the other day, and there's a water cooler with one of those 5 gallon tanks that you put in upside down, when i was getting a drink i saw the air bubbles going up into the bottle and it got me thinking.
would it be safe to use this as a chamber for combustion and/or pneumatic ? i know the mythbusters used one for a water-air rocket but i can't remember what psi they took it to

Image
  • 0

User avatar
Eddbot
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 434
Joined: Tue Oct 09, 2007 6:08 pm
Reputation: 0

Unread postAuthor: Novacastrian » Thu Dec 13, 2007 2:12 am

Defiantly good for a combustion, pneumatic yes but find out the pressure rating, i would not build a pneumo out of one. As a combustion it would be safe as banks so to speak, just don't restrict the flow with a tiny barrel, probably like a 4 inch barrel. Would be very loud.
If you make it take a pic when firing at night of the chamber, it would look awesome.
  • 0

America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.

Novacastrian
Major General
Major General
 
Posts: 1604
Joined: Sat Aug 11, 2007 6:59 pm
Reputation: 0

Unread postAuthor: Eddbot » Thu Dec 13, 2007 2:31 am

what would a 4" barrel accomplish? isn't the flow already limited by spout-nozzle thing?
  • 0

User avatar
Eddbot
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 434
Joined: Tue Oct 09, 2007 6:08 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Thu Dec 13, 2007 2:35 am

Eddbot wrote:what would a 4" barrel accomplish? isn't the flow already limited by spout-nozzle thing?


Take an 'acksaw to it ;) the length to weight ratio is ideal for combustions but I certainly wouldn't trust it as pneumatic.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: ALIHISGREAT » Thu Dec 13, 2007 2:43 am

jackssmirkingrevenge wrote:
Eddbot wrote:what would a 4" barrel accomplish? isn't the flow already limited by spout-nozzle thing?


Take an 'acksaw to it ;) the length to weight ratio is ideal for combustions but I certainly wouldn't trust it as pneumatic.


maybe he could getto it up and wrap it in duck tape then take it to 4 000 000 psi :twisted:

or you could just use it as a kick ass combustion... i have to find one of those i might get my dad to look aroud his office of something.
  • 0

User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: Killjoy » Thu Dec 13, 2007 4:17 am

Don't trust these drums for a pneumatic unless you reinforce it with say...fiber glass reinforced strapping tape. I used one of those in a pneumatic many, many years ago and it exploded between my legs, with chunks being found up to 20 feet away (though fortunantly I was not impaled).

This would be one kickass combustion though, expecially since it is clear. You could put a three inch barrel on it and shoot baseballs which would be sweet...
  • 0

Stanford Class of 2012

"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill

Killjoy
Brigadier General
Brigadier General
 
Posts: 1053
Joined: Sun Nov 12, 2006 12:51 am
Location: New Mexico
Reputation: 0

Unread postAuthor: The Kid » Thu Dec 13, 2007 4:34 am

yeah these things are dangerous and go off at about 90 psi and when it does you sure as hell don't want to be near it.
  • 0

User avatar
The Kid
Staff Sergeant
Staff Sergeant
 
Posts: 117
Joined: Sat Sep 29, 2007 7:50 am
Location: Australia
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: rna_duelers » Thu Dec 13, 2007 5:33 am

I thought it was more around the 50-60 psi mark if I can remember correct that these bursted on mythbusters.

Definite combustion!
  • 0

Image
User avatar
rna_duelers
Major General
Major General
 
Posts: 1740
Joined: Mon Sep 26, 2005 7:07 am
Location: G-land Australia
Country: Australia (au)
Reputation: 1

Unread postAuthor: watto » Thu Dec 13, 2007 5:42 am

I'm pretty sure mythbusters burst it at 90PSI
  • 0

User avatar
watto
Captain
Captain
 
Posts: 327
Joined: Wed Dec 13, 2006 5:47 pm
Location: Australia
Reputation: 0

Unread postAuthor: BigGrib » Thu Dec 13, 2007 5:55 am

Killjoy wrote:This would be one kickass combustion though, expecially since it is clear. You could put a three inch barrel on it and shoot baseballs which would be sweet...


I agree whole heartedly, just one question. Is a 3" barrel a "baseball" barrel? And if so abs or pvc and what sch.
  • 0

Yea, that's definitely going to get you at least a tazer.

<a href="http://www.youtube.com/watch?v=AkMkGOpAF4s">DONT TAZE ME BRO.. DONT TAZE ME... AHHHH</a>
facebook.com/biggrib
User avatar
BigGrib
Colonel
Colonel
 
Posts: 652
Joined: Mon Oct 01, 2007 11:43 pm
Location: TriCities, WA
Reputation: 0

Unread postAuthor: boilingleadbath » Thu Dec 13, 2007 2:21 pm

A baseball is 2.85-2.95" in diameter.

There isn't any barrel which will fit the lower end of that size range well, yet still fit the upper end of it; sch 80 PVC is 2.86, sch 40 is 3.04".

A 3" sch40 (PVC) barrel would be acceptable, I suppose, although a sabot would be a good idea.
**********

That said, there isn't any reason you can't use it as a pneumatic... just keep the pressure low. (I wouldn't use it above 30 psi)

A combustion may generate pretty significant pressures; I wouldn't trust this as a combustion chamber.
***********

Of course, I don't know the actual failure pressure of these things. Apparently, someone got one to fail at 90 psig, but that's a single datapoint...
Operating at 30 psi would give you a 3x safety margin.
  • 0

User avatar
boilingleadbath
Moderator
Moderator
 
Posts: 1642
Joined: Sat Mar 12, 2005 10:35 pm
Location: Pennsylvania, USA
Reputation: 0

Unread postAuthor: jimmy101 » Thu Dec 13, 2007 5:52 pm

The bottle would probably be OK for a basic combustion, but only as a novelty.

It should handle the pressure for at least a few firings, but I wouldn't stand anywhere near it when it is ignited.

There is a video out there of a Hydrogen + oxygen fueled water rocket built from one of those bottles ...

http://www.et.byu.edu/~wheeler/benchtop/pumpkin2.php
I think I can say reliably that 11.7 bar is above the engineering specs for water-cooler bottles.
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3127
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Unread postAuthor: JDP12 » Thu Dec 13, 2007 6:34 pm

Yea i wouldn't trust it for a pneumatic, even if it is rated fairly high, its just not built for it.

Go with a combustion definitely, the clear chamber would look AWESOME at night.

And I don't think you should use metered propane, just stick with hairspray, cuz i believe that someone said that metered propane has the potential to reach 90 PSI.

So just stick with hairspray or something similar IMHO, maybe i'm wrong, but i wouldn't trust it at its burst limit or very close to it.

Good luck with that build let us know how it turns out. :wink:
  • 0

"Some say his pet elephant is pink, and that he has no understanding of "PG rated forum". All we know is, he's called JSR. "
User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: bigbob12345 » Thu Dec 13, 2007 6:49 pm

Yea definatly do a combustion.
And I would recommend a very long 2in barel instead of a 3in or 4in you will get more power that way and just a warning on how loud and powerful this will be dont be anywhere near it when it goes off. And wear hearing protection even if you are 50 feet away( yes it will be that loud)
  • 0

User avatar
bigbob12345
Major General
Major General
 
Posts: 1516
Joined: Sat Dec 01, 2007 9:13 am
Location: Mercer Island,Washington
Reputation: 0

Unread postAuthor: DYI » Thu Dec 13, 2007 7:50 pm

Considering that the chamber is more than 12" ID, and that the most efficient combustion is a single pipe of a constant diameter, he will be gaining power by increasing barrel ID, except in the unlikely situation that the barrel ID is actually greater than the ID of the chamber. And unless he has a 6" or wider barrel, he needn't worry about having a barrel too long whether it is 2, 3 or 4".
  • 0

Last edited by DYI on Thu Dec 13, 2007 9:17 pm, edited 1 time in total.
Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Next

Return to Construction Materials/Ammo Discussion

Who is online

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

cron
Reputation System ©'