I was wondering if anyone would know where I could have a double headed coin made. I have both coins and would like to know if theres such a place or person that I could hire to have that done. thanks.
- posted
18 years ago
I was wondering if anyone would know where I could have a double headed coin made. I have both coins and would like to know if theres such a place or person that I could hire to have that done. thanks.
get two coins, mill them down to half thickness; solder the two halves together. Any machinist could do this. Whether they would want to is another matter.
I have done this several times with nickels. The instructions for it I found once in this news group. Quite easy to do.
Abrasha
Indeed. ...and *don't* mill both faces flat. The join is then way too easy to spot. Instead, turn a recess in one face, leaving the rim intact. Then turn the other coin to fit the recess. A good press fit won't require solder, and if turned coincident with the rim will be virtually undetectable.
A fun exercise - but if you just want a double-header, they're available for a few bucks on the 'net. Google is your friend.
-- Jeff R.
So, how do you hold it to turn down the rim?
:)
One way would be with a pot collet and a pressure pad in the tailstock.
The recess in the collet should be less than half the thickness of the coin - you'll need a setup like that anyway to face off half the thickness.
So the drill would be: Put coin in pot collet, apply pressure via tailstock pad to face of coin. Turn half the rim down to the reduced diameter. Then swap to the second pot collet, which has a diamter sized for the turned-down portion. Install the coin the other way around and turn down the remaining half of the rim diameter.
Then in the same setup pull back the pressure pad and carefully face half the thickness away.
The advantage of the bore and press approach is you can do this on coins with "coining" (the knurling around the circumference) without having to match up the knurling when supergluing them together.
Jim
Which would be better, super glue or solder?
What's the best way to hold the other coin, the one you bore out?
I'd think a soft collet recessed to suit ought to be safer than a chuck.
Jeff
OK, that's easy, but:
How do I hold it while I'm turning the OD, please?
Soft jaws. They don't crush or distort, nor do they move in a lateral direction when tightened, unlike a collet. They're also very fast and precise.
Harold
No, this is absolutely the wrong way to do this.
The right way is to bore out one side of one coin, do the same with a second identical coin, remove the edge of that second coin and then press fit that into the bored out space of the first coin.
Soldering two halves anneals the coins, and results in a coin that makes a thud on a hard surface when dropped. IF you are even capable of soldering the two halves together accurately which is highly questionable.
Using "my" (I did not invent this) method, results in a double headed coin, that sounds just like a regular one when dropped onto a hard surface.
Abrasha
Neither, press fit is the better solution.
...
See Jim Rozen's post, and also see text and pictures at:
-jiw
Thanks, James (and Jim)!
Dave
Correct these dollars are 1885 silver dollars.
"Lateral"? I'd call it "axial" like the collet and work moves along the axis of the spindle, toward the headstock, when tightened.
Then again, they do move laterally when viewed from where you usually stand relative to a lathe, so I guess either description is correct. :-)
They're also very fast and
Agreed,
Jeff
James Waldby wrote: > Dave Hinz wrote: >
Abrasha
They're far better suited to the application than a collet. Collets are influenced by the diameter of the object, so they don't close in the same place each time---limiting your ability to control thickness to some degree. If you have a Hardinge-Sjogren collet chuck, it's even more pronounced. Soft jaws, properly bored with a step, eliminate that problem and hold the coin perfectly perpendicular.
Harold
I used external gripping step collet from my lathe. I have a two sets of 5 internal and external step collets especially made for it. They worked perfectly for this.
See
Abrasha
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