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 Replies: 54 / Views: 2,269 |
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Pillar of the Community
 United States
6449 Posts |
  Still trying to get a handle on Machine Doubling. So I believe the 2012-D coin above shows MD on the Liberty and the 201. When compared to the 2012-P, the devices on the -D are withered. The "doubling" is shelf-like and not the same height as the original device. Yes?
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Valued Member
United States
449 Posts |
Yes, I believe you are correct sir.
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Pillar of the Community
United States
3207 Posts |
yes, your Denver minted coin exhibits Machine Doublinga problem with considering device width is that with Machine Doubling the devices appear narrowed only if you ignore the lower, shelflike area of each device, something rarely mentioned |
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Bedrock of the Community
United States
19110 Posts |
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Moderator
 United States
94636 Posts |
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Pillar of the Community
 United States
6449 Posts |
Cool beans. This is going up on ebay as an ultra-rare mint error. Starting bid, $685! =P Two things are still unclear to me about Machine Doubling. First, why does the device shrink in the first place? Usually wear makes things wider over time, not thinner. Second, why don't all the devices on a die wear relatively evenly? On this example, the Jefferson bust and In God We Trust look basically ok, even though Liberty and 2012 are badly deteriorated. |
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Pillar of the Community
United States
3207 Posts |
the devices don't so much as shrink as they get scraped while the die releases and the new coin twists
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Moderator
United States
94636 Posts |
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Pillar of the Community
United States
6449 Posts |
I do know that it's worthless. Hence the =P and jest about ebay. I will stick it in the album as a good example, just like the weak strike coin. |
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Moderator
United States
94636 Posts |
Quote:I do know that it's worthless. Hence the =P and jest about ebay.  ah, ok, that went way over my head, I missed the inflection. I guess I was thinking back on the other person that was selling pocket change as high dollar items... |
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Valued Member
Canada
219 Posts |
This is not Machine Doubling! Quote:
First, why does the device shrink in the first place? Answer given by nick10 is correct! Quote:
the devices don't so much as shrink as they get scraped while the die releases In this case upper design elements are not reduced. I did the following montage using Brandmeister's picture and original mint image from this link https://www.usmint.gov/coins/coin-m...o-monticello of the digits. The top images are the original pictures. For the middle images, I drew an outline on the outside edge of the digits of Brandmeister's picture, made a copy and pasted it over the mint's picture. This demonstrates the devices are not smaller but larger. For bottom images, I filled in the digits of the mint's picture, made a copy and pasted it over Brandmeister's picture. Again, this demonstrates that the devices are not smaller but larger. Thus, this is not due to machine doubling.  |
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Pillar of the Community
United States
3207 Posts |
@numidan, your reference image comes from a drawing of the mint's ideal coin made from fresh dies, whereas in practice the dies deteriorate such that the devices end up being larger than on a drawing
a coin made by a real doubled die with have two images of the devices, neither of which is flat like a shelf, instead if such a coin is viewed from an angle, both images will appear a bit rounded on their highest points above the fields
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Pillar of the Community
United States
6449 Posts |
Well, let's be precise about the cause. Is it Machine Doubling, Die Deterioration Doubling, excessive die polishing, or some other phenomenon? I've already learned quite a bit on this discussion. Such as the idea that the devices get thinner via scraping the walls of weathered die features during coin release. I had just assumed that the die features themselves got thinner over time. |
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Pillar of the Community
United States
3207 Posts |
A given coin can exhibit multiple irregularities, such as multiple forms of doubling, such as both DDD and MD. Even a given type of doubling can have multiple causes. For Machine Doubling the coin always twists relative to the die. If the coin is in contact with the die at the time of twisting, a scraping will occur, resulting a flattened portions of devices. It is also possible for the die to bounce, and strike the coin again but weakly, in which case portions of the devices are again flattened. Few collectors bother distinguishing between those two since neither makes for a more attrractive coin. |
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Valued Member
Canada
219 Posts |
Quote:
in practice the dies deteriorate such that the devices end up being larger than on a drawing You are right nick10, the devices are larger but not skewed in one direction! The deterioration being more severe near the rim as the outer rim of the die expands. Quote:
a coin made by a real doubled die with have two images of the devices, neither of which is flat like a shelf, Go and read the following topic (pages 2 and 3) showing it is not always the case: http://goccf.com/t/442616Quote:
instead if such a coin is viewed from an angle, both images will appear a bit rounded on their highest points above the fields In the image below, observe the highlights of the edge of the doubling and the devices, they have the same highlight gradation and width indicating they have the same edge profile.  Quote:
let's be precise about the cause Tanner believes it is Die Deterioration Doubling but I'm not totally convinced. What I can tell you for sure, it is not Machine Doubling. Edited by numidan
06/09/2023 1:30 pm
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Moderator
United States
94636 Posts |
As long as we are getting extremely nit-picky - we also need to remember that the devices are in a 3D view. when the devices are raised (as opposed to incuse) and looking from a very slight angle, we will see the sides of the device as it transitions from the top of the device down to the fields.  Edited by Dearborn
06/09/2023 1:34 pm
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Replies: 54 / Views: 2,269 |
Posted 06/08/2023 6:08 pm
