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 73 users online :: 3 registered, 1 hidden and 69 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

4 Shot Repeater Marble Rifle

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 

What size ABS pipe do you think is safe to use under 150 psi?

1.5"
1
8%
2"
1
8%
4"
1
8%
No ABS is safe to use
9
75%
 
Total votes : 12
  • Author
    Message

Unread postAuthor: Technician1002 » Thu Jul 01, 2010 5:25 pm

Thanks, I appear to stand corrected. This cracked in a normal combustion? Wow. From the way the cellular core hold up, this is very unusual.

Were there any unusual conditions that may have led to the failure? It looks like the female adapter cracked and the crack expanded into the pipe, not the other way around.
  • 0

User avatar
Technician1002
Chief of Staff
Chief of Staff
 
Posts: 5190
Joined: Sat Apr 04, 2009 11:10 am
Reputation: 14

Unread postAuthor: SpudBlaster15 » Thu Jul 01, 2010 6:26 pm

That failure was caused by a combination of an overtightened fuel meter fitting, and threaded holes in single layered pipe. It occurred way back in early 2007, and I've since developed much better construction techniques for advanced combustion launchers. Careful placement of threaded holes, use of an NPT tap to cut meter fitting connections, internal chamber fittings, and dual layering of chamber material in critical areas will reduce the risk of failure to a minimum.
  • 0

People should not be afraid of their governments. Governments should be afraid of their people.
User avatar
SpudBlaster15
Major General
Major General
 
Posts: 2385
Joined: Wed Oct 18, 2006 11:12 pm
Location: Canada
Country: Poland (pl)
Reputation: 3

Unread postAuthor: Ragnarok » Thu Jul 01, 2010 7:34 pm

To talk about a safety issue that isn't ABS related...

You need to watch where the muzzle is pointing rather more than you are at the moment. Between about 1:00 and 1:15 in that video, you've got the launcher pointing in just about every which way - while it's loaded.

Basic firearms safety is just as important, if not more so, with home-made launchers as it is with real firearms. While usually less energetic, they have rather fewer safety features, rather more chance of going off spontaneously, and are usually built from materials not intended for the purpose.
  • 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: Technician1002 » Thu Jul 01, 2010 9:22 pm

These things are not toys. Do treat them as if they are loaded at all times. I found this video of unsafe handling that could have ended poorly. This type of behavior is why many locations try to ban these. They are unsafe in the hands of unsafe people.
[youtube]http://www.youtube.com/watch?v=rgYyWJUXXNc[/youtube]
  • 0

User avatar
Technician1002
Chief of Staff
Chief of Staff
 
Posts: 5190
Joined: Sat Apr 04, 2009 11:10 am
Reputation: 14

Previous

Return to Pneumatic Cannon Database

Who is online

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

Reputation System ©'