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 39 users online :: 4 registered, 0 hidden and 35 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

Strength concerns

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

Strength concerns

Unread postAuthor: battlelava » Mon Apr 09, 2012 9:17 pm

Does anyone have a rough estimate at what galvanized pipe is good up to, its not rated for pressure but its 1/4" thick so i'm guessing it can take a few psi. And do you think that a stick welder with 6011 rods (60,000 tensile strength) is enough or should i go 70k tensile strength rods. I was going to start with a combustion which I know is not a problem, but for when i make it into a hybrid I don't want it to rupture.
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: Moonbogg » Mon Apr 09, 2012 11:43 pm

It depends on the diameter. It also depends on how the end caps are held in place. You can hydro test it before using it as a hybrid. Fill with water and pump with a grease gun at a safe distance.
  • 0

User avatar
Moonbogg
Major General
Major General
 
Posts: 1375
Joined: Mon Oct 13, 2008 10:20 pm
Location: whittier, CA USA
Reputation: 0

Re: Strength concerns

Unread postAuthor: jackssmirkingrevenge » Mon Apr 09, 2012 11:44 pm

battlelava wrote:Does anyone have a rough estimate at what galvanized pipe is good up to, its not rated for pressure but its 1/4" thick so i'm guessing it can take a few psi.


Inner/outer diameter? And what mix number do you plan on taking it to?
  • 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: battlelava » Tue Apr 10, 2012 6:51 am

Should be 1" inside and roughly 1.3 outside. All welded edges beveled and weleded with 6011 rods. Max of like 10x.
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Tue Apr 10, 2012 7:00 am

That looks about right :)
  • 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: battlelava » Tue Apr 10, 2012 7:14 am

Would it be good to go 1" to 2" diameter with a flatbar in the middle with a hole in it
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Tue Apr 10, 2012 7:43 am

At 10x that flatbar will have almost 2500 lbs pushing on it at the moment of firing, how comfortable are you with your welding ;)
  • 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

Sponsored

Sponsor
 


Unread postAuthor: battlelava » Tue Apr 10, 2012 8:03 am

I feel good about it, specially with the 6011 rods as they burn through galvanized like its nothing and i give it a little extra heat to really burn in and get good penetration. I could also do a multi pass. Should 3/8" flat bar be enough or should i go 1/2"


Or should I try to find a 2" to 1" reducer so there's no blunt surfaces for pressure to catch
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Unread postAuthor: Fnord » Tue Apr 10, 2012 5:37 pm

Crowley and SB15 have used 2" sch40 steel pipe in 10x hybrids, and perhaps DYI/killjoy have too. I've taken it that high with a sealed vessel. The threads on pipe present a thin spot of roughly half the normal wall thickness, so if you're welding it you will have additional safety factor. For 2" pipe I'd go with 1/2" thick end plates if you have them, but 3/8" would still be sufficient, just make sure to run a really thick bead.

Put another way... 2" pipe caps are *nearly* flat on the inside, And they're no more than 1/4" thick.
  • 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: battlelava » Tue Apr 10, 2012 5:54 pm

This pipes not threaded I was going to butt joint weld them together. I was going to ramp up the machine and really lay a fat bead like u suggested. I'm going to make a smaller version tomorrow. 3/4 barrel 2" chamber. Only 3/16 end plates and only low pressure 2x Max. See how well I can make this work
  • 0

User avatar
battlelava
Sergeant First Class
Sergeant First Class
 
Posts: 142
Joined: Wed Oct 26, 2011 9:13 pm
Reputation: 0

Return to Construction Materials/Ammo Discussion

Who is online

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

cron
Reputation System ©'