Author Topic: Piece of Bronze shafting...  (Read 2902 times)

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Offline flagman1776

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Re: Piece of Bronze shafting...
« Reply #30 on: August 18, 2011, 05:25:21 AM »
No CNC machines in 1943!   

Offline Cat Whisperer

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Re: Piece of Bronze shafting...
« Reply #31 on: August 18, 2011, 08:09:18 AM »
16 decimal place accuracy for calculating WINDAGE.  A GOOD slide rule will give you 4 and that's good enough for me.
 ;D
Tim K                 www.GBOCANNONS.COM
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Offline flagman1776

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Re: Piece of Bronze shafting...
« Reply #32 on: August 21, 2011, 12:23:41 PM »
I completed the bore
 

Offline GGaskill

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Re: Piece of Bronze shafting...
« Reply #33 on: August 21, 2011, 07:44:02 PM »
Some bronzes really don't weld well.  The welds crack when cooling and all other kinds of undesirable things.  It would really help to know what one is welding.

On the other hand, if you have enough to experiment with, samples can be welded to see what happens.
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

Offline flagman1776

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Re: Piece of Bronze shafting...
« Reply #34 on: August 22, 2011, 03:38:17 AM »
Thinking back many years, when I was in the marine trades, propellers were welded all the time.  However, propeller shafts were not. 

Offline flagman1776

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Re: Piece of Bronze shafting...
« Reply #35 on: August 23, 2011, 04:01:16 AM »
In researching the archaic terms "Brass" & "Bronze" in the world of modern alloys is meaningless.  The same alloys can be called by either label.

Offline GGaskill

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Re: Piece of Bronze shafting...
« Reply #36 on: August 23, 2011, 09:31:09 PM »
Modern practice is to call copper alloys with zinc as the main alloying element "brass" and those with something else as the main alloying element "bronze."  The best way to refer to any copper alloy is with the Copper Industry Association numerical code.
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

Offline flagman1776

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Re: Piece of Bronze shafting...
« Reply #37 on: August 24, 2011, 04:24:19 AM »
Thanks GG for this useful information to direct my research. 
Russ

Offline flagman1776

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Re: Piece of Bronze shafting... There is a Santa Claus!
« Reply #38 on: December 26, 2011, 09:11:22 AM »
 
My Bronze shaft Mortar Project reached an impass...  my limited equipment & skills mandated outside help.  I sent my pieces...  to a skilled metalworker.   Upon reciept, he evaluated my pieces & my "make do" plans & suggested that there was a better way to proceed.  He suggested turning the breech to a true hemisphere & using a matching ball end mill to machine the trunion.  I readily agreed.  He was kind enough to provide me with periodic progress pictures:

Before

After cutting Hemisphere
 

He made a fixture to hold the trunion shaft

Milling the trunion

The trunion pocket

Test fit the trunion on the barrel.  Flawless machine work & perfect fit. 
This is just a huge step up from what I had envisioned looking at the original cut off with an existing cut (which I eliminated in my initial breech turning.)   I shipped out salvaged junk & got a Mortar back!  The vision to look into a piece & see what it can become is priceless. 

Unanticipated Problem!  The welding gave him fits...  the unknown alloy just did not want to weld.  I hope we are still friends after this.  I had no idea it would be a bow-wow! 
Shipped 2 days before Christmas (flat rate, if it fits, it ships!)  Amazingly, I recieved it 2 days later, after noon on Christmas eve.  I will dress the weld a bit after I recover from Christmas.   See there is a Santa Claus!   

Offline Cat Whisperer

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Re: Piece of Bronze shafting...
« Reply #39 on: December 26, 2011, 01:40:58 PM »
COOL -

I'd thought YEARS ago of doing it that way but didn't have the ball endmill nor the ability (at that time) to do the hemispherical end.

Looks like the Dremmel Moto Tool will come in handy.

Keep the pix coming!
Tim K                 www.GBOCANNONS.COM
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Offline flagman1776

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Re: Piece of Bronze shafting...
« Reply #40 on: March 29, 2012, 03:07:00 PM »
My friend had the opportunity to get the piece he trimmed off the trunion analyzed and the result was C462 Naval brass.  He reports not finding welding properties listed for this material.   
I understand his frustraton after the effort he put into making the fixtures needed, shaping the rear of the barrel into a hemisphear & the cup in the trunion only to have the welding not give the professional appearance he expected.   I started with the dremel & it will clean up fine.   

Offline jamesfrom180

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Re: Piece of Bronze shafting...
« Reply #41 on: March 30, 2012, 05:05:01 AM »
Does that mean you will go back and through bolt to reinforce the weld? Is it possible with this piece, enough meat at the rear of the chamber for a few threads?  ::)
AMMA Bosslopper 1988

Offline flagman1776

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Re: Piece of Bronze shafting...
« Reply #42 on: March 30, 2012, 09:18:13 AM »
The 2 pices of shafting are welded solidly if not as pretty as he wanted...  Because of the oversized trunion and the cup machined in it, it left adequate beef...  I'm confident it will not flex.   I feel that installing bolts would weaken it rather than strengthening it. 
I posted this data because at one point we were discussing what to do with the other 16" piece of 1 1/8" propeller shafting I got from that same source that day...   

Offline jamesfrom180

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Re: Piece of Bronze shafting...
« Reply #43 on: April 02, 2012, 07:42:50 AM »
Very cool looker and sounds like it should shoot good.   8)
AMMA Bosslopper 1988