A little advice or tips on dd

What exactly am I looking for in doubled die coins . I don't know why it's so hard for me to actually see this? Any advice tips or anything would be appreciated. I have a USB microscope and Jewelers loupe. Thanks for your time .

 

Log in or Sign up to hide this ad.

Here is a website I want to share with you - http://www.doubleddie.com/58222.html

 

Also these -
http://lincolncentresource.com/doubledies/doubledies.html

https://www.pcgs.com/News/What-Is-A-Doubled-die

Here is a PDF file with great information also

 

Wow very informative thank you so much !

 

I always had a hard time figuring this out myself. Pictures are great but having one in hand, it is a lot easier to discern.

 

So, "doubled die coin" is an error coin? It isn't so. It is die error, but, not error coin. They already knew from first few strikes that the coin hub wasn't precisely aligned, it was slightly off the center. By knowing that, the error in the die, they continued to strike. So, that doubled die coins were produced wasn't a surprise, was expected. So, these doubled die coins aren't error coins.

 

I believe those that were MDO which was in the master hub, such as on the 72's, were released on purpose, a DDO, is usually caught and quality control tries to remove as many of them as possible, Though they are an "error" I think they are better defined as "Variety's".

 

Of course it's an error coin, in most cases caused by a misalignment of the master die. Nothing wrong with the die itself...I think...LOL
http://doubleddie.com/58222.html

 

Ok, I read some part of that strike/forge technique which I am not very familiar with and summarized the process as follow:

Master design -> Master Hub -> Master Die -> Working Hub -> Working Die -> Coin

So, where is the error here? It is in the misalignment of "Master Die" and it is a part of the production process. They already knew that the resulting coin would have been different than the designed coin and they still continued to produce. So, ok, this can be called "production process error", but, not the product error as they already knew the result. So, I don't call it error coin.

 

I could be wrong, but, I believe that DD happens in the Working hub process.

 

Doesn't matter whether it happened in the master hub or die or working hub or die. They all are in the production process and DD is a production process error. Technically, when it is said "error coin" any engineer in the industry will consider it as "product error" rather than "production process error". With production process error, all products are produced are same and engineers know final products in advance. I guess DD too is such a product, same product in all strike with the same die. Anyway. I am not posting this to re-stimulate this almost dead thread.

What I have seen is that. Coin collectors are searching errors in coins, ok, but, they are searching errors only in the mint. Yes, there are engineering errors also in the mint, but, those errors are insignificant. Main error is somewhere else. In the setup.

 

OK, it's a coin caused by an error...but NOT an error coin??

 

When the term "error coin" is used it implies "everything in the production process was normal, but, a coin was produced with an error". Error is an unexpected thing which is realized later after the production. But, these Doubled Die coins were expected, were known in advance because the mint engineers knew the outcome as they were aware of the problem with the die (or hub or whatever in the production process.) (keep banging your head.)

 

I dont believe that a mint employee goes thru the working dies with a loupe to see if it is doubled. The DD is usually caught after the striking process has begun, and the mint try's to remove them if found.

 

Is there any DD in latest coins of last decades? I don't think so. In last decades, those die toolings are being made at CNC (computerized numerical centers machines) which have good tolerances. Therefore, probability of such errors during the die making process is minimum nowadays. And, before a coin production starts, tests are made. In old days, when they were using mechanical machines such as lathes, milling machines, etc to make the dies etc they were not so accurate and making strike/forging dies are difficult and expensive. I am sure in old days too they tested first and saw the DD, but, they let the production process go. So, according to the mint people, these DD coins were not error coins, was not a surprise to them, they knew it before anyone discovered.

 

Also, they are no longer hubbed as before, thus called the single squeeze die production. The Doubling occurs as the die "slips" or changes position in the striking process and not a part of die preparation. Many consider the single squeeze DD as really a MDD coin, but different strokes for different folks.

 

I can't take it anymore!! I've become a DDZ doubled die Zombie!
Yes, YES! I need a cold beer!

 

This die "slips" or position change is happening at new technology machines or was happening at old machines? I didn't understand this. In the reference links given above, it is told that the DD errors were sourced from the dies or the hubs.

 

Doubled die error coins can fetch significant prices when they are noticeable to the naked eye or occur in a popular coin series. One example of this is the 1955 doubled die Lincoln Wheat cent.

Doubled dies are created when the hub imprints an additional, misaligned image onto a die. There are many ways this misalignment of images can occur, which have been classified into eight accepted classes:

Class 1, Rotated
A class I doubled die results when the die receives an additional hubbing that is misaligned in a clockwise or counterclockwise direction.
Class 2, Distorted
A class 2 doubled die results when the hub's design moves toward the rim between hubbings.
Class 3, Design
A class 3 doubled die results when a hub bearing a different design stamps a die bearing another design.
Class 4, Offset
A class 4 doubled die results when the die receives an additional hubbing that is misaligned in an offset direction.
Class 5, Pivoted
A class 5 doubled die results when the die receives an additional hubbing that was misaligned via rotation with a pivot point near the rim.
Class 6, Distended
A class 6 doubled die results when the die receives an additional hubbing from a hub that was distended.
Class 7, Modified
A class 7 doubled die results when the hub is modified between the die's hubbings (e.g., a design element was chiseled off).
Class 8, Tilted
A class 8 doubled die results when a die and/or hub is tilted during a hubbing.

 

I believe since 1986, the process of single squeeze to make a working hub began, The classic doubled die as Fish lists above was for the previous "more than 1 press" to make a working die. Maybe this reference will help
http://www.coinnews.net/2014/01/06/how-the-denver-mint-makes-dies-to-produce-coins/