Doubling on laser produced dies?
Insider2
Posts: 14,452 ✭✭✭✭✭
I just saw an image of a doubled "DO" in the Counterfeit Detection Column in the February 2019 Numismatist magazine. The anonymous writer claims that the doubling resulted from a laser. I find this very hard to believe. I thought lasers made precise copies. Can any member with tool and die making experience comment? Does a laser turn a "D" into a shape resembling a doubled "D?"
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May I see the pictures?
Would a laser be able to replicate metal flow using high-end software or AI?
US Mint dies are cut with Micron mechanical cutters that are computer controlled. No lasers were collimated in this response.
There have been incidents what could loosely be called a Class III doubled die on modern proof coinage. The main hub imparts the design as normal, and then the laser puts the nasty 60-grit frosting on the coin, sort of acting as a second hub of a different design. If there's a misalignment between the die and the laser, you'll see, for example, a frosted letter next in the field to an unfrosted one in extreme cases, and the traditional "split serifs" of a doubled die in the more minor cases.
I'll have to look at the article to see what the writer is asserting regarding a laser faking a doubled die.
Keeper of the VAM Catalog • Professional Coin Imaging • Prime Number Set • World Coins in Early America • British Trade Dollars • Variety Attribution
The coin in the article was made with a Counterfeit die. I have no image as it is in the article; however, think of a "D/D" with a split serif that looks like it is a doubled die.
Image provided by the ANA's Numismatist magazine. The anonymous writer claims that the doubling resulted from a laser used to make the counterfeit die.
Using a laser to add "frost" is not "die cutting."
I sort of see what you mean BUT the laser must "cut" into the die in order to leave the granular surface that is markedly different from other parts of the die. Are we all just posting the same thing?
Would that not be a die made by EDM transfer? I could see if the electrode(piece being copied) shifts something like this happening.
Collector, occasional seller
OK, "Die ablation."
Keeper of the VAM Catalog • Professional Coin Imaging • Prime Number Set • World Coins in Early America • British Trade Dollars • Variety Attribution
I'm confused about the question. Is this an accidental doubled die cut with a laser? Is it an intentional doubled die cut with a laser? Is it a laser copy of a doubled die original?
The US Mint does not cut dies with a laser.
Looks like chatter. If you don't vibrationally isolate your system and/or your laser and die are spatially separated, vibrations will cause the laser to dither a bit resulting in the "doubled" image.
For the second time. This is a counterfeit coin struck with a counterfeit die. Nothing done at the US Mint has anything to do with my question.
Someone wrote that the doubling on the counterfeit happened when a laser cut the counterfeit dies. This appeared in our national organization's magazine. Sounds like some uninformed, misinformation by a rookie (?) authenticator. I sincerely hope I'm wrong. That's why I asked this:
"I just saw an image of a doubled "DO" in the Counterfeit Detection Column in the February 2019 Numismatist magazine. The anonymous writer claims that the doubling resulted from a laser."
I'm here to learn. This involves die making with a laser. I am completely ignorant on the subject!
So this IS a laser error? Hard to believe but you must know more than I do. So the laser "chattered" because it is NOT die chatter by any stretch.
With the apparent micro fabric texture, that does look like a laser-cut die.
I think the die may have shifted between laser passes.
Vibration artifacts are common while doing high-resolution low power laser scanning of models for 3D printing... Several of my clients must use concrete and stone vibration wells, or fix the artifacts in modeling software... Short of asking the counterfeiters about the processes used in their nefarious pursuit, it seems that one could just as easily assert that the die cutter sucks.
Check out my current listings: https://ebay.com/sch/khunt/m.html?_ipg=200&_sop=12&_rdc=1
Within 10 years the best expert will not be able to detect counterfeits. The inaction of those that know better will kill our hobby. Ebay, Amazon, Etsy, et al facilitate the sale of counterfeits unabated. These U.S. companies using the "we can't police everything because it costs so much" excuse and the FTC sitting on their thumbs makes the profit in this too much for the Chinese to ignore. The fact that no one is doing anything of any substance is allowing the fraudsters to fund the advancement of their technology to the point where counterfeits will be indistinguishable from the genuine.
All I can do is complain while Ebay makes millions and the crooks make 9x that. (minus the tiny cost of production)
I am afraid that those with the power to force action will wait until it's too late to change anything before forcing compliance with the US laws. The time is rapidly approaching where the crooks will have the money and technology to circumvent the too little too late enforcement of the HPA/CCPA.
There are collectors that have the resources to force the changes necessary to protect Collectible Coins . If they don't use that influence NOW to make Ebay and the others change NOW, it will be useless when they decide they have to.
If YOU don't do something to stop the money flow, we are all dead in the water.
Just My Opinion
Ed
http://www.silverstocker.com
Anyone can PM me Any Time about Any thing.
The sky is falling! Newsflash Mr. Ed,
You can shut down Ebay, forbid any coins from being imported, and fix anything else you wish to bring up. THAT WILL NOT STOP COUNTERFEITING. That will also not stop counterfeiters from improving their product which has been going on for countless decades!
As for ten years, that's also incorrect. State-of-the-Art fakes have been undetected by most experts ALSO for decades. The only 100% protection anyone has is to know what the genuine coin should look like down to the 40X level of magnification and that is beginning to be too little. Since the early 1980's I've claimed that the days of the hand lens for coin authentication are over. I was a little off on my timing. Here are some things to consider.
The knowledge of the "expert" is an important requisite and they better not get complacent. I hate to embarrass him here, but during an ANA Summer Seminar in the 1970's, Ken Bressett, Charles Hoskins and myself were examining some counterfeit error coins after class. Charlie and I were sharing a Zeiss stereo microscope while Ken had a hand lens - 10X as I recall. We would point out something we saw on the coin using the scope at high power,and Ken would see it and then point out other things just as important with his magnifying glass! Experience, experience, experience makes up for a lot of things.
Next, in a Boston seminar for Adelphi, Univ. in the early 1980's I told the class I had been examining coins at high power using a stereo scope for a very long time. I told them that I believed there was no one on earth who had seen the surface of so many coins at 40X and over. I told them if any of the "young, present day expert authenticators" started doing it tomorrow, they could never catch up to me or my experience. THEN I SAID THIS to a student who was a scientist which is one point I'm making in this post: "If you were go back to your lab tomorrow, and start examining the surfaces of genuine coins using your SEM, you would surpass my expertise in a short time and after a few months and thousands of coins, no one would ever surpass the total number of coins you've examined with an SEM!
Right now there are genuine coins that have been impounded in museums around the world for decades before the counterfeits (except for ancients) got any good. Hopefully, they will be scrutinized using high power magnification so that authenticators will be able to stay one step ahead of the crooks.
The TPGS's are our front line of defense. Additionally, in this internet age, with access to images, the counterfeiters have a much tougher job. Jim Young, a member of this forum and a group of his friends are detecting state-of-the-art fakes by comparing online images. AFAIK, they have no formal training as authenticators yet they are helping the "experts" at several TPGS's.
Thanks to all posters who educated me about the doubling defect that can be caused by a laser.
Interesting thread.... Having used lasers (when in pre-retirement business), I was aware that doubling due to product vibration/movement was possible. At that time, it was not even a consideration for coins (though removal of surface flaws on gold was rumored). I did see doubling of identification lettering by lasers when done on product.... never equated that with coins at the time. Cheers, RickO