| Author |
 Replies: 19 / Views: 7,431 |
|
Pillar of the Community
United States
6370 Posts |
So, I am a student at Georgia Tech. I recently heard that we may be getting a metal 3-D printer (at a $600,000 price tag!) within the next few years, which means that will have potential access to one. So my question is: If I ever get permission to use the printer, will the membership here be interested in my doing exploratory research in attempting to 3-D print a coin and a pair of dies? I will NOT be using them to actively counterfeit coins, and they will be promptly cancelled or donated to the ANA after good observation, pictures, and tests are made. Without the intent to deceive, and with the intent to experiment and share my findings, would this be illegal under the Hobby Protection Act? I don't think it would. Prod #9: Though they look like tools, they were actually made for use as money in China back before 200 BC. |
|
|
|
Moderator
 United States
56855 Posts |
How about making a CCF token? John1  |
|
Pillar of the Community
United States
1191 Posts |
You should "print" a car that goes 10 mph I believe. Heard it on the new last year.
Now about your question, I agree with John1, a token would be better than a coin. If a coin falls in the wrong hands, who knows what will happen. But I would love to own one!
|
|
Pillar of the Community
 United States
6370 Posts |
Well, I want to see how easily and with what results I can replicate an actual coin with minute details (Morgan Dollar, per se) by 3-D scanning it, CAD up the coin and a set of dies, and print them. Once observations and tests are done, they would be promptly cancelled and/or donated to the ANA. However, I could find a token with minute enough detail that would satisfy the parameters of this experiment. |
|
Pillar of the Community
United States
500 Posts |
What a great life experience for you typecoin to get to do a project with a $600,000 piece of equipment as a student! Congrats
|
|
Rest in Peace
United States
17900 Posts |
There are a number of great state centennial and bicentennial and sesquicentennial tokens (or medals) that are every bit as detailed as our coinage.
Trying one of those might be a good choice, since you wouldn't have to worry about being accused of counterfeiting, regardless of your intentions.
It would be great for you to follow up to see how and where you could get the machine to stamp the coins/tokens/medals as well as the planchets to stamp them from.
Having an "all in" cost to actually produce, or reproduce an item in silver, for example, would be of interest to everyone, I'm sure.
|
|
Pillar of the Community
United States
711 Posts |
Don't 3D print dies. 3D print the coin directly. Release the design files so other people can mint your currency. You can invent the world's first open source precious metal currency. Back in the day the US Mint would take your bullion off the street and mint coins on demand. With a 3D printer you could do that again. For those without access to a $600,000 machine, I have used http://www.shapeways.com to purchase 3D printed parts in the past without a 3D printer of my own. I believe they do produce items in silver for anyone interested. This way you just have to produce the file and they will print it for you. Basically why buy the cow / printer, when you can get the milk / printed item for a minimal charge. |
|
Bedrock of the Community
Australia
21786 Posts |
To use a 3-D printer to make a die involves using a coin to copy from in the first place.
Once the die has been made, it has to be hardened.
The die would then used to strike fake coins.
3-D printing has been in use for quite some time, including the manufacture of turbine blades for jet engines. This approch to manufacture is used to eliminate internal stress within the turbine blade.
There are other modern approaches to making fake dies for the striking of fake coins.
One of these methods include laser optic profiling of a coin's surface to made a cyberspace image, and using that image as data to cut a die by the spark erosion process.
In the detection of fake coins their method of manufacture, irrespective of that method of manufacture, provides the basis of investigation to expose a fake coin for what it is.
The instrumentation to carry out such investigations ia almost always in advance to the methods of fake coin manufacture.
The same approach to investigation is used, when it comes to the manufacture of genuine coins, be they be from ancient or modern times.
|
|
Rest in Peace
United States
17900 Posts |
Well said, Sel. The tech will be on the side of the good guys after all.
|
|
Valued Member
United States
171 Posts |
There are various ways to "scan" an existing coin to collect 3D topographic data.
These methods include touch-probing and photogrammetry.
I do not, however, believe that such data can be used in any type of spark-erosion process.
But it could potentially be used with a computer-controlled milling/engraving machine.
Due to the nature of how 3-D printing works, any fakes produced by that technique will be identifiable.
The reason is that a 3D printed coin will have the characteristics of a CAST coin, not a STRUCK coin.
3D printing can not replicate the internal stresses in a struck coin which produce the luster and ring tone.
|
|
Bedrock of the Community
United States
17884 Posts |
Quote:Well, I want to see how easily and with what results I can replicate an actual coin with minute details (Morgan Dollar, per se) by 3-D scanning it, CAD up the coin and a set of dies, and print them. Once observations and tests are done, they would be promptly cancelled and/or donated to the ANA. Once you do the scan, can't you alter the file to incorporate the legally required word COPY so it would be in relief on the die (and therefor incuse on the coin as legally required.) Not that it matters, I seriously doubt yout printed dies would be able to be hardened and successfully strike coins. A printed coin might be interesting to see, but I think it would be easily identified as a fake. |
|
Bedrock of the Community
Australia
21786 Posts |
A printed coin of identical alloy as the real thing would not have the same upset metallic crystalline structure as a struck coin. The metallic crystalline surface structure of a printed coin would be very different.
That is why you would have to print the dies, not just the coin.
The differences in metallic crystalline structure between a printed coin and a struck coin would form the basis of an investigation to distinguish a fake coin from a genuine one.
|
|
Bedrock of the Community
United States
20753 Posts |
A price of a few hundred thousand dollars would be nothing to some criminals. And I'm sure many have already put in their bids on such machines. Just one more thing for counterfeiters to use on everything.
|
|
Bedrock of the Community
United States
17884 Posts |
Quote:
A printed coin of identical alloy as the real thing would not have the same upset metallic crystalline structure as a struck coin. The metallic crystalline surface structure of a printed coin would be very different.
That is why you would have to print the dies, not just the coin. And those same structural problems are the reason the printed dies would not survive striking coins. I would think there would be nearly immediate collapse of the die surfaces from the force of striking. |
|
Valued Member
United States
127 Posts |
From what ive seen on cheap 3d printers is they lack the resolution to be perfectly seamless. Like when someone gets a plastic toy printed, you can see the layers all stacked together to form the object. Granted, a super expensive metal printer is more sophisticated than a $3000 maker bot or whatever but id imagine you could see the resolution lines on a 3 printed die or coin under a microscope. Or maybe not? Maybe they are that good now.
|
|
Moderator
United States
187702 Posts |
|
| |
Replies: 19 / Views: 7,431 |
Posted 11/21/2015 11:01 am
