Author Topic: Patchbox hinge - forming from sheet  (Read 9672 times)

Offline Acer Saccharum

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    • Thomas  A Curran
Patchbox hinge - forming from sheet
« on: June 28, 2012, 04:39:45 AM »
Hinge forming block, thanks to Mark Elliott's idea. I think Mark had a tutorial on hinge forming on the old ALR. Anyway, I made up one of these for getting that nicely formed hinge barrel. The block has a a round top tab, about .08. The hole closes down as you work the hinge, it works down to about a 1/16" pin hole.

Making the sharp inside corner. anneal after this step. Use a nice sharp cornered block to form on. The vise jaws are a little too messy to get a good clean bend over.


Formed corner and forming block. Anytime you make a sharp bend like this, anneal the brass afterwards. If you don't anneal, the brass can crack at the next bend. To Anneal: heat the brass to dull red and dunk in water. It will be dead soft again.


forming block and hinge piece clamped up with the corner of the brass tight against the forming block.


gradually pry the tab up with a chisel, until you get the tab up high enough where you can use the hammer to start wrapping the brass around the nosing of the forming block.


Hinge tab bent up and over the nosing bead of the block


Partially formed barrel. Anneal when this step is complete. Now scrub both inside faces clean, as they will be soldered after the last step.


Hold wire in groove with a turnscrew while tapping tab over with a hammer.


peen tab over until snug. A hardened music wire pin is necessary, or you will have trouble pulling the pin after you're done forming. Pull the wire, and hard solder the seam.



I missed a few pictures along the way, but this is the end result. .06 brass, curved finial and door. Seam is tight when shut; when the door opens, so does the seam.


I formed the barrels over .062 wire, but the pin now is about .04. When I fit the knuckles, I reamed it out to .062 wire size.


Soldered folded over and doubled hinge area. The hinge knuckles have to be in a pretty straight line for the hinge to be able to open. If the hinge has too much curve, and the pin is snug in the barrels, the HINGE AIN'T GONNA OPEN.

« Last Edit: February 26, 2013, 09:40:57 PM by rich pierce »
Tom Curran's web site : http://tcurran.com/

Offline Acer Saccharum

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Re: Patchbox hinge - forming from sheet
« Reply #1 on: June 28, 2012, 04:48:38 AM »
Flintriflesmith has a tutorial on his site for forming a curved hinge.

Follow this link:

http://www.flintriflesmith.com/ToolsandTechniques/making_a_curved_box_hinge.htm
Tom Curran's web site : http://tcurran.com/

Offline Curtis

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Re: Patchbox hinge - forming from sheet
« Reply #2 on: July 05, 2012, 12:27:07 AM »
Great tutorial, Acer.  Thanks for taking the time to take the pics and posting them with the accompanying test.

Curtis
Curtis Allinson

NMLRA Gunsmithing Seminar and Workshop at WKU~ http://www.nmlragunsmithingseminar.org/
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Sometimes, late at night when I am alone in the inner sanctum of my workshop and no one else can see, I sand things using only my fingers for backing

Offline Cory Joe Stewart

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Re: Patchbox hinge - forming from sheet
« Reply #3 on: July 07, 2012, 05:28:11 AM »
Thank you my friend.  This came at a perfect time for me. 

Coryjoe

Offline E. Smith

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Re: Patchbox hinge - forming from sheet
« Reply #4 on: July 08, 2012, 01:08:38 AM »
Many Thanks, Tom.
"Three things prompt Men to a regular discharge of their Duty in time of Action, Natural bravery—hope of reward—and fear of punishment."       George Washington