Author Topic: wall thickness  (Read 685 times)

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Offline bert-nc

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wall thickness
« on: July 06, 2010, 02:36:43 PM »
I have read that the wall thickness of the powder chamber should be the same as the bore of the powder chamber.
However, is there any rule of thumb on the wall thickness of the barrel?

bert-nc

Offline GGaskill

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Re: wall thickness
« Reply #1 on: July 06, 2010, 02:53:53 PM »
I would say you're OK if the wall tapers from 1:1 at the front of the chamber down to 25% of bore at the muzzle, but you don't want any part so thin that it is not sufficiently strong enough to resist ordinary bumps and bangs.

And don't take this as allowing the use of water pipe for any cannon barrel parts.  It is not strong enough.
GG
“If you're not a liberal at 20, you have no heart; if you're not a conservative at 40, you have no brain.”
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Offline Double D

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Re: wall thickness
« Reply #2 on: July 06, 2010, 03:39:40 PM »
Muller Treatise does have a formula for various sections of the barrel.  If you scale and follow the dimensions of an original gun you should be just fine.

Once you  have made a few guns and understand the principals you can branch out an free lance.

Offline bert-nc

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Re: wall thickness
« Reply #3 on: July 06, 2010, 05:09:51 PM »


And don't take this as allowing the use of water pipe for any cannon barrel parts.  It is not strong enough.

don't worry about that, I have read enough on this forum to know that is unacceptable

bert-nc

Offline dan610324

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Re: wall thickness
« Reply #4 on: July 07, 2010, 01:39:18 AM »
on old drawings they show approximately 50% of the bore diameter as the smallest wall thickness in the muzzle area and 100% or slightly more in the chamber area
this was for bronze cannons

for iron cannons the walls around the chamber should be between 125 to 150% of the bore diameter

its clearly visible on the 2 mid 1700 drawings below

on the drawing for the bronze cannon you can see all measurements
they show in parts of the caliber
Dan Pettersson
a swedish cannon maniac
interested in early bronze guns

better safe than sorry

Offline brokenpole

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Re: wall thickness
« Reply #5 on: July 07, 2010, 08:53:16 AM »


And don't take this as allowing the use of water pipe for any cannon barrel parts.  It is not strong enough.

don't worry about that, I have read enough on this forum to know that is unacceptable

bert-nc

It is certainly nice to see a new person on the boards who has read the threads and understands why these guys say what they say and believes in it!!

Offline GGaskill

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Re: wall thickness
« Reply #6 on: July 08, 2010, 12:33:30 PM »
I might add for clarity that the 25% number applies to the thinnest area near the muzzle.  Any muzzle banding would be in addition to the 25% thickness.
GG
“If you're not a liberal at 20, you have no heart; if you're not a conservative at 40, you have no brain.”
--Winston Churchill