What cannon parts should I machine?

A place for general potato gun questions and discussion.
Dave_424
Specialist 2
Specialist 2
Posts: 220
Joined: Thu Aug 02, 2007 7:45 am

Hey guys, recieved my lathe a while ago and am not sure what I want to build from some scrap metal I have.

I have about 8 inches of 1 1/3" brass bar and don't really want to waste it on making smaller parts.

I was thinking about making a really high mix hybrid. Having about 10mm walls.

What mix roughly (I know it is very hard to guess) would be achieveable?

Dave
User avatar
Moonbogg
Staff Sergeant 3
Staff Sergeant 3
United States of America
Posts: 1737
Joined: Mon Oct 13, 2008 10:20 pm
Location: SoCal
Has thanked: 169 times
Been thanked: 102 times

Totally dependant on the alloy. Which alloy is it?

EDIT: Brass is simply not brass, just like a bolt isn't just a bolt.
Dave_424
Specialist 2
Specialist 2
Posts: 220
Joined: Thu Aug 02, 2007 7:45 am

no idea to be honest, just use the weakest alloy and ill see if I like the mix number
User avatar
Moonbogg
Staff Sergeant 3
Staff Sergeant 3
United States of America
Posts: 1737
Joined: Mon Oct 13, 2008 10:20 pm
Location: SoCal
Has thanked: 169 times
Been thanked: 102 times

A quick stress analysis based on a common brass yield strength of 37kpsi, the safety factor on 1,000psi is 15. On 3,000psi its 5. This doesn't take into account any form of end caps you may use, its only the strength of the tube itself. Based on this quick study I would go for 15-20x. Drill a single hole in the chamber anywhere and your safety factor drops by about HALF!
Dave_424
Specialist 2
Specialist 2
Posts: 220
Joined: Thu Aug 02, 2007 7:45 am

Okay then, Not really sure what to do then.

What do you suggest I make from this and other scrap pieces?

Dave
User avatar
psycix
Sergeant Major 4
Sergeant Major 4
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands

If you would drill a hole in the side (at the back of the chamber), simply use a smaller inner diameter there.
Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

  • Similar Topics
    Replies
    Views
    Last post