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 35 users online :: 5 registered, 0 hidden and 30 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Exabot [Bot], Google [Bot], Majestic-12 [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Hybrid max mix with PN16 PVC?

Post questions and info about hybrid (compressed gas with fuel) powered cannons here. This includes discussion about fuels, ratios, ignition systems, build types, safety, and anything else relevant.
Sponsored 
  • Author
    Message

Hybrid max mix with PN16 PVC?

Unread postAuthor: RedAplle » Thu Sep 18, 2008 7:29 am

Hi there,

I'm planning about making a hybrid launcher from 50mm PN16 PVC, but I'm wondering about the max mix I could get from it?

Thanks, and sorry for my bad english =/
  • 0


RedAplle
Private
Private
 
Posts: 17
Joined: Tue Jan 22, 2008 7:55 am
Reputation: 0

Unread postAuthor: CpTn_lAw » Thu Sep 18, 2008 8:24 am

PN16 PVC is RATED to 16 bars, or 240 psi...That is equivalent if I am not mistaking to a 3x mix. each mix has a potential pressure peak of around 80 psi...correct me if I'm wrong. I'd say you'd be safe with a 3x mix, now do what you want but be aware of the risks...
  • 0

"J'mets mes pieds où j'veux, et c'est souvent dans la gueule."
User avatar
CpTn_lAw
Brigadier General
Brigadier General
 
Posts: 987
Joined: Sun Sep 11, 2005 9:10 am
Location: France
Reputation: 0

Unread postAuthor: JDP12 » Thu Sep 18, 2008 9:32 am

sorry to disagree with you, but NO!

i wouldn't really care if it was rated to 500 PSI, its not the PSI itself that causes PVC in hybrids to explode, its the extremely rapid pressure spike- the PVC cannot handle it.

I believe every hybrid made out of PVC has exploded, even though it was rated to the pressure, it was the pressure SPIKE that did them in.

just go with a steel one, and keep things alot less dangerous
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: RedAplle » Thu Sep 18, 2008 4:55 pm

So even if I just use it with à 2x mix (that is approx 160PSI, if CpTn_lAw is right), it could explode because of the fast compression in the pipe?

Ok, so I'll try to see if I can found something else, like galvanized steel.

Thanks a lot!
  • 0


RedAplle
Private
Private
 
Posts: 17
Joined: Tue Jan 22, 2008 7:55 am
Reputation: 0

Unread postAuthor: Fnord » Thu Sep 18, 2008 7:07 pm

I believe every hybrid made out of PVC has exploded, even though it was rated to the pressure, it was the pressure SPIKE that did them in.


BS.

SOME have exploded. Enough to consider them unsafe at least.

Also, Redaplle, You should probably try a couple basic combustions /pneumatics before you try a hybrid. You'll save yourself a lot of frustrations.
  • 0

Image
User avatar
Fnord
Major General
Major General
 
Posts: 2244
Joined: Tue Feb 13, 2007 9:20 pm
Location: Pripyat
Reputation: 7

Unread postAuthor: RedAplle » Thu Sep 18, 2008 7:25 pm

Don't worry about it, I have already made a combustion and few pneumatics (my last one shoots 10mm steel balls at 200m/s, using 35bar :)).
  • 0


RedAplle
Private
Private
 
Posts: 17
Joined: Tue Jan 22, 2008 7:55 am
Reputation: 0

Unread postAuthor: SpudMonster » Thu Sep 18, 2008 7:48 pm

ilovetoblowthingsup wrote:I believe every hybrid made out of PVC has exploded, even though it was rated to the pressure, it was the pressure SPIKE that did them in.



Brilliant observation, and completely false. Hybrid failures, while they can happen, are extremely rare.
  • 0

Stupid quote of the now:
joestue "The chamber is rated to 100 psi, it don't say that on the side, but the 2 inch stuff is rated to 300, so by analogy..."
"only the last two feet hear the end is black cellular core"
"I'm taking it to 300 psi"
User avatar
SpudMonster
1st Lieutenant
1st Lieutenant
 
Posts: 250
Joined: Mon Aug 08, 2005 5:54 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: RedAplle » Thu Sep 18, 2008 7:57 pm

So I can make my PN16 PVC hybrid without any problem if I don't use it at more than a 3x mix?
  • 0


RedAplle
Private
Private
 
Posts: 17
Joined: Tue Jan 22, 2008 7:55 am
Reputation: 0

Unread postAuthor: jonnyboy » Thu Sep 18, 2008 8:04 pm

Dude just use steel. It's a little more expensive but you'll be able to use higher (funner) mixes. It might not fail if used in the cold the pvc is more brittle more likely to burst. I don't care what the pvc is rated to i wouldn't want to be near the thing when it fires.
  • 0

mobile chernobyl wrote:I can shoot a Canuter Valve off my '82 Chevy Ram F150 AT LEAST 3/4 Mile with 'ma cannon made of soup cans duct taped together, then I just squirt some bacardi 151 in the chamber and hold up my cigarrete lighta and WHOOSH! That thing flies at least 3/4 mile
User avatar
jonnyboy
Colonel
Colonel
 
Posts: 591
Joined: Mon May 26, 2008 1:20 pm
Location: Williamston MI USA
Reputation: 0

Unread postAuthor: RedAplle » Thu Sep 18, 2008 8:13 pm

Yep, but I wanted to use PVC because I have 6meters of 50mm PN16 PVC (I had this for about 20$)...
  • 0


RedAplle
Private
Private
 
Posts: 17
Joined: Tue Jan 22, 2008 7:55 am
Reputation: 0

Unread postAuthor: brplatz » Thu Sep 18, 2008 9:19 pm

if its $20 bucks your worried about then a hybrid is probably not the best option.

A well built (and safe i might add) will cost you about $100 on the cheap-end using steel. My motto is build it right or don't build it at all. i am fortunate enough that my friend works at ace hardware and gets amazing discounts, but don't skimp when it comes to safety. :)
  • 0

"Any problem on Earth can be solved with the careful application of high explosives...the trick is, not to be around when they go off" Col. Mertz Von Quiriheim
User avatar
brplatz
2nd Lieutenant
2nd Lieutenant
 
Posts: 222
Joined: Fri Mar 21, 2008 12:21 am
Reputation: 0

Unread postAuthor: RedAplle » Thu Sep 18, 2008 10:06 pm

The pipe I use are really good. It's not because it's only 20$ that it's bad material. I also have good discounts.

I have already made plans for one in steel, and it should cost about 60$, but I don't want to spend 60$ on it. I prefer spend my cash for pneumatics :P
  • 0


RedAplle
Private
Private
 
Posts: 17
Joined: Tue Jan 22, 2008 7:55 am
Reputation: 0

Unread postAuthor: brplatz » Thu Sep 18, 2008 10:53 pm

I never said it was bad material. its just that in the interest of self-preservation I recommend doing it correctly.

The price means nothing. $20 for what? How much of it did you get? What quality?

I don't want to be a downer on your hybrid-building parade but i do like to see things done right and the builder happy and safe in the end.

In the end its truly your call. Have fun and be safe
  • 0

"Any problem on Earth can be solved with the careful application of high explosives...the trick is, not to be around when they go off" Col. Mertz Von Quiriheim
User avatar
brplatz
2nd Lieutenant
2nd Lieutenant
 
Posts: 222
Joined: Fri Mar 21, 2008 12:21 am
Reputation: 0

Unread postAuthor: psycix » Sun Sep 21, 2008 2:23 pm

Simple explanation:
Hybrid cannons do not only produce more pressure, they also produce bigger shockwaves and pressure spikes.
PVC is a material which cannot withstand repeated shocks like that.

An PVC hybrid can never be considered safe: sooner or later, they simply start to form micro cracks and fail.

So I can make my PN16 PVC hybrid without any problem if I don't use it at more than a 3x mix?

No. You can't.
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Unread postAuthor: SpudFarm » Sun Sep 21, 2008 3:26 pm

you guys over estimate this a load to much, a 2x mix in a PW chamber (in this case PN16) is about the same as setting of a combustion mix in a DWV chamber, the biggest problem you will have is heat. if you constict flow it WILL melt your chamber where it goes over to the smaller diameter.
  • 0

"Made in France"
- A spud gun insurance.
User avatar
SpudFarm
Donating Member
Donating Member
 
Posts: 2563
Joined: Sat Nov 04, 2006 9:39 am
Location: Norway Trondheim area
Reputation: 0

Next

Return to Hybrid Cannon Discussion

Who is online

Registered users: Bing [Bot], Exabot [Bot], Google [Bot], Majestic-12 [Bot], Yahoo [Bot]

Reputation System ©'