Need some ideas on expanding the outer edge

US coins are made by either roll bonding or explosion welding the three layers. Roll bonding is done by heating the metal and rolling under high pressure to achieve the bond. Explosion welding is done by stacking the layers and using an explosive charge atop one layer to force the layers into intimate contact with each other, creating the bond.
 
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It's called "cladding" and more resembles a weld at the molecular level. Copper moves into the nickel layer and vise versa.

Step 1 should be finding the collet you need to fix a half dollar to your lathe and hollowing a few out. Seems like there are a couple of useful ideas for expanding the hollow shell. At $0.50 per attempt, there's no reason not to see what works.
 
I don't think it is practical to expand the perimeter of a hollowed out coin. Even if you can expand part of the edge, the junction between the edge and the face will be rounded.
You might have success by cutting away the interior of the coin leaving a rim and then stretching that so an OEM coin can fit inside. A third coin would be faced to a thin disk and silver soldered to the expanded rim to create the container. There will be a small line of silver solder corresponding to the clearance fit for the OEM coin but it should be unnoticeable under casual inspection. Before facing the coin, the edge could be worked to expand the diameter slightly for a closer fit.

As I recall, it was John Saunders, NYC CNC, that did a video on cutting down a coin. I believe that he glued the coin down with super glue.

I would mount a piece of aluminum in the lathe and machine a pocket for a snug fit of the coin. Then, I would glue a coin in with super glue and machine the coin. When finished, the assembly can be trimmed to remove excess material and the remainder of the aluminum dissolved away with a dilute sodium hydroxide solution. The super glue can be removed with actone or, more quickly, with Goof Off ™ super glue remover leaving the machined coin behind.
 
RJSakowski said:
I don't think it is practical to expand the perimeter of a hollowed out coin. Even if you can expand part of the edge, the junction between the edge and the face will be rounded.
You might have success by cutting away the interior of the coin leaving a rim and then stretching that so an OEM coin can fit inside. A third coin would be faced to a thin disk and silver soldered to the expanded rim to create the container. There will be a small line of silver solder corresponding to the clearance fit for the OEM coin but it should be unnoticeable under casual inspection. Before facing the coin, the edge could be worked to expand the diameter slightly for a closer fit.

As I recall, it was John Saunders, NYC CNC, that did a video on cutting down a coin. I believe that he glued the coin down with super glue.

I would mount a piece of aluminum in the lathe and machine a pocket for a snug fit of the coin. Then, I would glue a coin in with super glue and machine the coin. When finished, the assembly can be trimmed to remove excess material and the remainder of the aluminum dissolved away with a dilute sodium hydroxide solution. The super glue can be removed with actone or, more quickly, with Goof Off ™ super glue remover leaving the machined coin behind.
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holy s*** thats a good idea btw i bought a press yesterday just to try something similar
 
RJSakowski said:
I don't think it is practical to expand the perimeter of a hollowed out coin. Even if you can expand part of the edge, the junction between the edge and the face will be rounded.
You might have success by cutting away the interior of the coin leaving a rim and then stretching that so an OEM coin can fit inside. A third coin would be faced to a thin disk and silver soldered to the expanded rim to create the container. There will be a small line of silver solder corresponding to the clearance fit for the OEM coin but it should be unnoticeable under casual inspection. Before facing the coin, the edge could be worked to expand the diameter slightly for a closer fit.

As I recall, it was John Saunders, NYC CNC, that did a video on cutting down a coin. I believe that he glued the coin down with super glue.

I would mount a piece of aluminum in the lathe and machine a pocket for a snug fit of the coin. Then, I would glue a coin in with super glue and machine the coin. When finished, the assembly can be trimmed to remove excess material and the remainder of the aluminum dissolved away with a dilute sodium hydroxide solution. The super glue can be removed with actone or, more quickly, with Goof Off ™ super glue remover leaving the machined coin behind.
Click to expand...
silver solder is that a special kind of solder or is all solder silver solder ?
 
pontiac428 said:
It's called "cladding" and more resembles a weld at the molecular level. Copper moves into the nickel layer and vise versa.

Step 1 should be finding the collet you need to fix a half dollar to your lathe and hollowing a few out. Seems like there are a couple of useful ideas for expanding the hollow shell. At $0.50 per attempt, there's no reason not to see what works.
Click to expand...
already have my collets made and for my quarter too and for my englis and centavos
 
remember this name 2 to 5 years from now if we havent been depopulated by the tyrants that be We Build Ilusion will be one of the main magic makers thats the goal and working on negotiations with collectors work Shop.
 
RJSakowski said:
US coins are made by either roll bonding or explosion welding the three layers. Roll bonding is done by heating the metal and rolling under high pressure to achieve the bond. Explosion welding is done by stacking the layers and using an explosive charge atop one layer to force the layers into intimate contact with each other, creating the bond.
Click to expand...
uh that part doesnt sound right i use to make silver coins and bars we used dies
 
addertooth said:
Another classic is using a modern zinc core penny, score one side, then toss in nitric acid. It will eat the zinc out of the copper-clad penny and produce a shell, which a dime will fit perfectly in. The old turn a penny into a dime trick. Because the colors are not similar the change is from penny to dime is very clear. Because the copper "shell of a penny" is very thin when the zinc core is removed, it can simply be easily crushed into a BB sized wad of copper (thus ridding any evidence that the "penny" ever existed. No carefully milling or expanding a rim required.
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yes i also plan on make nickels to dimes and the one i think you are talking about is a matchbox put penny on someones hgand and place matchbox on top penny changes to the dime and penny reappears inside the matchbox
 
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