Classes of doubled dies

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(trying to get this in a post we can find easily when searching)
Some good examples:

Class 1 rotated hub doubling, think of it as 2 images with a nail through them in the center then one image rotated. (rotated like a wheel on an axle)

http://coppercoins.com/lincoln/diestate.php?date=1955&die_id=1955p1do001&die_state=eds

Class 2 distorted hub doubling, think of it as the diameter of one image is bigger than the other so you see doubling to or from the center to the rim. The cause might be that one hub was newer and one older, the older one tends to be spread out towards the rim.

http://coppercoins.com/lincoln/diestate.php?date=1946&die_id=1946s1do005&die_state=mds

Class 3 design hub doubling, think of it as 2 images but the images are not the same design. On this one it was a small date design over a large date. The RPM is not related, it just happens to be there for un-related reasons.

http://coppercoins.com/lincoln/diestate.php?date=1960&die_id=1960d1do001&die_state=mds


Class 4 offset hub doubling, think of it as 2 images over eachother but the center of one is not over the center of the other so it wasn't centered the same.

http://coppercoins.com/lincoln/diestate.php?date=1983&die_id=1983p1dr001&die_state=mds


Class 5 pivoted hub doubling, think of it as 2 images with a nail through them at some point along the rim. On this coin the nail would be at 4:00/K4. Because of that the least shift is near the pivot point and the most shift is opposite to it:

http://coppercoins.com/lincoln/diestate.php?date=1995&die_id=1995p1do001&die_state=eds

Class 6 distended hub doubling, think of it as the extra wide distorted ones. It's probably caused because one die was treated differently and destorted. The combination of distorted plus normal makes it wider.

http://coppercoins.com/lincoln/diestate.php?date=1943&die_id=1943p1do001&die_state=mds

Class 7 modified hub doubling, lets say they change the design during the year and one has a different date position. They modify by grinding away the date then they fix it or do a second hubbing using a new hub. You still see a remnant of the old design that was not fully removed. (my desc is not great)

http://coppercoins.com/lincoln/diestate.php?date=1970&die_id=1970p1do002&die_state=mds

Class 8 tilted hub doubling, they do one hubbing with the hub tilted so it makes a partial image. The second image should cover it if it's flat. We might only notice these if the second image is shifted by another reason so we still see the tilted partial image. Most doubled eylids are from this.

http://coppercoins.com/lincoln/diestate.php?date=1970&die_id=1970p1do001&die_state=mds

Class 9, single squeeze hub doubling, think of it as putting your hand in mud then moving it. You get a wide image but no seperation.

http://coppercoins.com/lincoln/diestate.php?date=2006&die_id=2006p1do007&die_state=mds