2012 Jefferson Nickels: Machine Doubling Identification, Attempt #2.

I am surprised Silvio by your comment , a man of science like yourself should see the value of knowledge. It is not always about a quick buck!




It is the first time I have heard about this terminology. From the description and pictures shown it is nothing more than Machine Doubling. Why come up with this new terminology? Maybe Coop can explain what he saw that was different.




Sorry but I am not one of those. My research have led me to conclude that it is either caused by a Die Deterioration or a doubled die.

I am limited on the amount of US nickels I can get so right now I can not rule out Die Deterioration as I have not found two coins produced the same year, having the same exact doubling, and with different deterioration states.

Doing a quick search on this forum, you will find many posts of nickels have very similar type of doubling as this one.

Nick, you make a valid point. I am accustomed to doing root cause analysis for low level software and high level digital microprocessor design (which is essentially just specialized code converted into a physical set of chip manufacturing tools by computer). In all those cases, I have the final product, the original code base, the manufacturing tools, the original requirements and design, and everything in between. Obviously I must reach the answer to all customer-found problems. The final test case must be isolated into something repeatable, possibly over hundreds of runs, before we make any changes to fix it.

Or at least you should. I've seen a lot of people hack at a code base over the years until their bug stopped appearing. That's a great way to play Whack-A-Mole with bugs until your field guys break out the pitchforks and torches and invade your cubicle.

For a coin, all we have is the final product, often in a worn or partly deteriorated state. In order to get to a true root case, you're right, I'd basically need a mint. Then I'd need a mint expert's knowledge to troubleshoot the problem.

I did read somewhere about convex dies. The degree of curve is not something I know. Is that why Machine Doubling is seen more around the rims? I had kind of assumed that it's identified more around the perimeter because that's just where the lettering happens to be, and those devices tend to stand the highest from the field at a sharp angle (vs a bust, for example).

Sorry I do not look for quick buck. Do I need this quick buck? Answer is No.

The point for me here it is ,and I appreciate very much Brand, was when I wrote that him put to much effort for something which in the end will be "Blowing in the wind" do to the fact that will reach not many peoples. The rest will simply say is MD because theirs horizon in very close. I know this as a person who has now 383 Academia papers and studies.

Brand, In the same direction if you want a very interesting subject it is Hub Doubling and because the Die from any reason slip, move , etc. majority will say MD. Yes has something from MD but the base?

About your Mechanical Doubling (ejection). This in fact apply better to vertical presses as was Graebener (this it is the correct name AE in fact it is an A two points up), and was see on the Reverse.

I appreciate Silvio's question about why not focus effort on hub doubling. Many people find hub doubled coins to be valuable. Coins diagnosed as machine doubled are seen as worthless. But why is that? I would wager that a great many of those people perceive hub doubles as valuable because a few experts suggested that was so. If the experts suddenly changed their mind, then the value would plummet.

For me, the virtue of "true" doubling vs. "mechanical" doubling is not so clear. Both are man-made mistakes in the coin manufacturing process, but at different stages. I have not found a convincing argument for why hub doubling is so valuable, except that it is 1. repeatable across multiple coins, 2. it is perceived as rare.

Compare hub doubling to other minting errors. Broad strikes and multi-strikes are dramatic mistakes. Die clashes are visually unusual. Die cracks, Cuds, chips capture a story about the mechanical minting process.

But I don't know that die doubling is any more compelling than, for example, a repunched mint mark. Somebody had a shaky hand on the first swing of the hammer. Or somebody struck a die a second time a tiny fraction of a radian out of alignment. Is a microscopic split serif considerably more valuable than the nickel that started this conversation? I don't know.

Honestly, with an ounce of perspective, the whole hub doubling obsession seems 80% as silly as a value premium for toning. You stored your coin in a contaminated environment and now the surface metal has chemical discoloration. But good news, the discoloration is a pretty concentric rainbow so +1 to MS grade for Hufflepuff. Huzzah!

It's a hobby where some dude paid $40000 for a Roosevelt dime struck on a nail. I guess it's good that nobody cleaned the nail or PCGS might have graded it Details. Therefore, I'm not quite willing to uncritically accept what is commonly accepted as valuable or not.

@ Brandmeister:

I mention the Hub Doubling because the origins of those Doubling go back to the master Die and offend are confound with MD. the DD's resume to the Working Hub. Personally I do not care about the value and I care more of the variety. Will be nice if you and Numi will come with an exponential on this cloudy topic.