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Looking for information on stamping coins

MetalArtistCandy

Aluminum
Joined
Jun 1, 2017
I just purchase a Gold machinery CMC 230 ton jewlers and coin press.

Would love to know how to get dies, have the dies made for the coins I want, and then best way to get the coin materials. Is it cheaper for 5000 pieces to buy blank coins, or make them?
 
Pantographs used to be used in fabricating coining dies, but have generally been replaced by machinery operating from digital files. Good pantographs are sometimes available at not much more than scrap prices, but have usually been separated from their accessories. You would need a pantograph with three dimensional capability in order to create a die from a model. Early mint operators used punches and gravers in creating their crude coining dies which were used with hammers. Find a copy of Numismatic Forgery by Charles M. Larson for a good summation of the many ways of creating fake coins. This book is intended to provide the collector with information on how fakes are made to help him detect coins that are not genuine. As mentioned, Kevin Potter’s site has a lot of information. Watch his video associated with his reasonably priced 100 ton press. If you attempt to replicate any US coins include the word copy in your dies to avoid legal problems.
 
I just picked the machine up today. One of the guys at the company gave me some good andvice and showed me how it works. He said they use another company who makes their dies with a cnc machine.

Also where can I get D2 steel? He mention that for the dies.

Also said I need to figure out what kind of a resess I need on the dies or could leave a sharp burr or something like that.
 
"Ah, but a man's reach should exceed his grasp, Or what's a heaven for?"

Your questions suggest a significant naïveté, but perhaps if I'd had your "go for it" attitude I'd have gone farther in life.

D-2 is a tool steel that has good strength, hardness, and wear resistance. Other tool steels that are used in coining dies include A-2 and O-1 and proprietary steels. You usually machine the stuff in annealed (soft) condition, then harden and temper with heat treatment. Sometimes precision ground post-HT. Two things: Heat treatment can change dimensions a little bit. A-2 is more dimensionally stable than D-2. It machines more easily, too. Last, its heat treatment is a little simpler.

Here is more info on tool steels: https://www.daytonlamina.com/sites/default/files/dayton_tech-balancing.pdf

For sources, google tool steel and email or call the source you find for pricing and delivery. Other guys here buy more tool steel than I do, so they may be able to guide you.

Two places to start your sourcing:
McMaster-Carr
MSC Industrial Supply | Metalworking and MRO Supplies
 
I have actually used a similar press once or twice, with very crude dies I plasma cut from mild steel, to basically emboss sheet metal. Nowhere near the complexity and precision of the dies you need for coins. But one thing I know- watch your fingers. 230 tons, instantly, is nothing to trifle with. People who are used to hydraulic presses think this may be like them- but its actually much more like a very controllable, small, OBI punch press. 230 tons in a very small box, moving at incredible speeds. Although jewelry coining presses like this usually allow adjusting the tonnage of the hit, so you can fine tune for various metals and dies.
 
Hello,

I spent about 3 months restoring and setting up a drop hammer to produce silver dollar sized coins. With the help of some folks on here, and a little bit of cowboy "engineering", I have a machine that produces many coins each day.

Bosleyjr is right on target with the steel choices. I had a set of dies made out of 01 and they are holding up under less than ideal conditions (hard, repeated impacts) quite well. Message me for the manufacturer I used.

In terms of blanks, I would highly recommend Regency Mint. Their service and shipping has been outstanding, and they did a custom run of aluminum blanks for me, and I've had no trouble ordering brass and copper blanks as well.
Regency Mint - Precious Metals & Custom Coins produced by Regency Mint Regency Mint

Once again, message me and I can provide you with an email address for whom I've been working with there. Fantastic folks.

Unless you have a punch press to make these blanks, I would definitely say it's cheaper to order them through a mint wholesaler that has the machine ready to crank those out. They come either burnished or tumbled, and just the time savings alone is worth ordering them. No metal waste, no machine wear and tear, and none of your time eaten up making your own blanks between the punching, tumbling, and finishing.

For the coins I'm making, with the size at 1.5" and the thickness around .102", the ideal depth of engraving would be around .030-.050" but definitely not much more than that. Most times an engraver knows their steels if you can specify what machine you're going to run the dies in. Now they don't always know what depth to engrave to, and that's critical. When the depth of the engraving is too deep, your coins will come out looking like Ruffles potato chips from the amount the metal moves. I am speaking from experience.

230 ton should be more than enough to make some beautiful coins. I am curious to hear about your efforts!

my post for reference:
Double Strike Issue
 
What software can I use to create a 3d image for a cnc shop to create my dies? Will the cnc shop be able to convert the inage to code for their machine, or is that something I have to do?
 
You need it 3D... you have to draw/make it 3D. Pay an artist on Fiver to do it and it’ll be a HELL of a lot cheaper than paying a machine shop to stumble through it at $75-125/hr for something they have never done. That’s not machining it’s art. Customers typically provide blueprints not request they 3D model an image. 3D modeling is a skill set. Most of us do it everyday... making an image a 3D coin model? I wouldn’t touch that for $10,000. I’d waste too much time and too high risk of “No, not like that. More like this other thing I didn’t know I wanted...”
 
3D modelling is a skill - relatively hard.

It is easy to learn, but has endless critical-path gotchas.
So it takes several hundred hours to learn to get decent models.

Anyone can make a 3d model flat round + some text details in a few hours.
Specified depths, fillets, corner rounds - and polygon counts/accuracy is quite different.

I would expect to spend about 1 month on a "good" copy of a modern coin. 200 hours.
Not excellent, good.


You need it 3D... you have to draw/make it 3D.
Pay an artist on Fiver to do it and it’ll be a HELL of a lot cheaper than paying a machine shop to stumble through it at $75-125/hr for something they have never done. That’s not machining it’s art. Customers typically provide blueprints not request they 3D model an image. 3D modeling is a skill set. Most of us do it everyday... making an image a 3D coin model? I wouldn’t touch that for $10,000. I’d waste too much time and too high risk of “No, not like that. More like this other thing I didn’t know I wanted...”
 
3D modelling is a skill - relatively hard.

It is easy to learn, but has endless critical-path gotchas.
So it takes several hundred hours to learn to get decent models.

Anyone can make a 3d model flat round + some text details in a few hours.
Specified depths, fillets, corner rounds - and polygon counts/accuracy is quite different.

I would expect to spend about 1 month on a "good" copy of a modern coin. 200 hours.
Not excellent, good.

Exactly. 200 hours? That's skill. I'm sure I could spend a year and still not love the results.

The only way I have seen it done is by hand modeling/sculpting it in real world at a much larger scale from (clay?) then they mold the negative from that and use a pantograph to scale that mold and machine it into the die which maintains impressive detail. That first link provided was pretty freakin cool though. Technology.... amazing. I keep meaning to call and get a price on those lasers.
 
The oversized model followed by reduction with a pantograph used to be very common. My grandfather did a lot of this. When I was a kid, it wasn’t unusual to walk into his shop and see 12 inch McDonalds forks and 6 inch Monopoly racing cars or boots carved from wood to serve as pantograph masters.

Jon
 
Ive got to figure out if this machine is 3 phase. I assume it is since it has a 3phase plug... but wanted to double check. I cant see any info on the pump and electronics.
 
We’ve got a royal mint just up the road from me in llantrisant, they use the already mentioned reduction pantographs, I went on a visit to the Concast plant where they cast the strip for coins years back, once they make the wax master they reduce it onto a copper and edm the thing from what I saw, though some were cut most seem eroded, the presses double strike, I thing they said 600 tons on the press, if you type royal mint as a search they have videos of coin making, when I was there they were making US coins, and Canadian as well, funny story bit you have to strip and wear a paper tyvec suit in the bits where the money is, no pockets btw, it was odd seeing bins of euro coins being melted
Mark
 








 
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