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1971- D Kennedy Half - Double Eye Lid!

 
 
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 Posted 10/06/2019  11:08 pm Show Profile   Bookmark this topic Add Sarge50 to your friends list Get a Link to this Message
So this is just Mechanical? Why is it not anywhere else?




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 Posted 10/06/2019  11:12 pm  Show Profile   Bookmark this reply Add Sarge50 to your friends list Get a Link to this Reply
Better obverse picture!


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 Posted 10/06/2019  11:58 pm  Show Profile   Check Errers and Varietys's eBay Listings Bookmark this reply Add Errers and Varietys to your friends list Get a Link to this Reply
Yep, just Machine Doubling. Machine Doubling can happen anywhere.
More information about Die Deterioration? http://goccf.com/t/317950
Retired U.S. Mint Coin Die Set information. http://goccf.com/t/302961
Machine Doubling Tutorial. http://goccf.com/t/332421
Die states progression on coins. Scroll down, so you can see the different die state progressions. http://goccf.com/t/325638
Die Deterioration Doubling Tutorial. http://goccf.com/t/336470
Split Plate Doubling Tutorial. http://goccf.com/t/357614
2000 P LMC With Retained Struck Through error. http://goccf.com/t/357080
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 Posted 10/07/2019  10:30 am  Show Profile   Bookmark this reply Add Earle42 to your friends list Get a Link to this Reply

Quote:
Why is it not anywhere else?

When a coin is struck under such hard and fast pressure the metal is forced to flow (think of the molecules being moved - which is what is happening) into the die's devices at a very fast rate. If we were one of those molecules, the forces all around us are not equal since various areas of the die details can accept more volume (deeper impressed devices on the final coin), or less. Therefore some molecules by us will be more rapidly flowing into the larger openening between the dies for deep er devices while other areas will become hardened as a bottle neck situation occurs with some molecules trying to fit into smaller cavities.

All this means different areas of the metal will be more prone to movement than others. So some of the softer areas will be more susceptible to the smearing of Machine Doubling if the dies are loose.

Granted - all of the above is just a hypothetical guess from someone who has taught physics - but not specifically concerning metallurgy. I am applying general physics theories to how material will react. Sometimes the physics of a specific material is changed under rapid high pressure conditions. Also, the heating up of the metal during this process may also dictate other properties I know nothing of.

I am putting this out as theory for correction by someone who knows more about metallurgy in minting coins.
- When I value " being right" more than what IS right, I am then right...a fool.
- How much squash could a Sasquatch squash if a Sasquatch would squash squash?
- Real men play Fizzbin.
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 Posted 10/07/2019  3:05 pm  Show Profile   Bookmark this reply Add Sarge50 to your friends list Get a Link to this Reply
Earle42....that makes total sense about flow of metal with high pressure And heat Causing a flowing of metal thus a Mechanical error or MD! Thank you for that scientific explanation!
Edited by Sarge50
10/07/2019 3:06 pm
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 Posted 10/07/2019  5:05 pm  Show Profile   Bookmark this reply Add coop to your friends list Get a Link to this Reply
Actually John Wexler was at the mint and he got to see a coin struck and they handed it to him. But he mentioned the coin was not hot at all. (which surprised him also) So heat has nothing to do with it. Kind of the like the saying. It wasn't the bust on the train tracks that damaged the bus, but the train that hit it. So after the coin was struck, on the way up from the coin, die movement damaged the fresh new devices. (The train that damaged the coin in this case)
Richard S. Cooper
Some have asked about my images I use and I'm glad to say, you can now you can see the DVD in sections on youtube:
1. Intro, older coins, toned coins 2. Doubled dies 3. Die events, One of a kind errors 4. So called errors, Coin information 5. Coin information Types and Varieties, Overlays
Jefferson nickel doubled dies Wexler/Rebar complete listings

trail dies:http://www.traildies.com/
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 Posted 10/07/2019  8:29 pm  Show Profile   Bookmark this reply Add Earle42 to your friends list Get a Link to this Reply
Coop thanks for this clarification. So in other words the metal is successfully moved into all the devices with the die design correctly transferred, but the upward moving die "snags" (sort of) on its way upward from the coin? And this snag/move smears the newly made device? I assume the majority of the coin's mass resists the snagging movement b/c the freshly stamped devices are still resting inside the grooves that constitute the engraving in the die?

I admit I do not undersrand only one device (or part of a device) can therefore be smeared/doubled if there are not areas less density in the coin metal that was caused by non-uniform flow of metal into various areas of the design that will allow more or less metal to enter? Something I am missing makes does not let me understand how when the die moves sideways, since its in contact with the entire surface of the newly minted coin, the entire design is not mechanically doubled?

- When I value " being right" more than what IS right, I am then right...a fool.
- How much squash could a Sasquatch squash if a Sasquatch would squash squash?
- Real men play Fizzbin.
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 Posted 10/07/2019  8:56 pm  Show Profile   Bookmark this reply Add coop to your friends list Get a Link to this Reply
There is sometimes more bounce after the strike that makes this happen almost field lever, sometimes half way up and other times touching the upper part of the devices. It all depends on the looseness of the machine. This can occur differently from strike to strike:

Note the markers are all the same. These coins were is the same OBW roll. Note they are different from strike to strike and sometimes repeating patterns on other examples I found in the roll. Note on these examples the push of the dies moved and like pushed snow, pushed upwards from the movement and push of the machine.
Richard S. Cooper
Some have asked about my images I use and I'm glad to say, you can now you can see the DVD in sections on youtube:
1. Intro, older coins, toned coins 2. Doubled dies 3. Die events, One of a kind errors 4. So called errors, Coin information 5. Coin information Types and Varieties, Overlays
Jefferson nickel doubled dies Wexler/Rebar complete listings

trail dies:http://www.traildies.com/
Edited by coop
10/07/2019 8:58 pm
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 Posted 10/08/2019  09:59 am  Show Profile   Bookmark this reply Add Earle42 to your friends list Get a Link to this Reply
I like your pushed snow analogy.

I need to think more on this. I can understand what you are saying about it happening at different depth levels as the die retracts upwards. I am still having trouble figuring out how the die, still in contact with many deivces as it is being raised, can only affect, like shown above, the 5s and not, let's say the 9 and 1 which are so close to the 5.

At present I may be missing something still. To me it seems, in some of your pics above, that since only the 5s were plowed aside, that only the 5s were in contact with the die and nothing else on the coin was? Its just difficult for me to envision this, maybe if I were a molecule on the coin's surface when it was being stamped I would better understand?
- When I value " being right" more than what IS right, I am then right...a fool.
- How much squash could a Sasquatch squash if a Sasquatch would squash squash?
- Real men play Fizzbin.
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