Strange consistent strike doubling / shelf?

Aspie_Rocco

I was inspired by recent newcomers to search a few OBW coin rolls last night and I came across several 2013 D nickels with what appears to be identical strike doubling. Except some of the doubling has texture (not all flat) and looks almost tripled under a microscope.
Input, thoughts, opinions, and “not again “ comments welcomed.

Aspie_Rocco

After more searching I have found a nearly identical strike on just a few in 2011 D 2012 D and 2013 D nickels. This is a photo of a 2011D with apparent doubling of the right side of the window above the O of Monticello

BuffaloIronTail

BUT.......BUT......BUT.......with the new single squeeze that's NOT supposed to happen.

Pete

RogerB

Mechanical doubling is a product of worn or improperly adjusted equipment. Nearly identical doubling can be imparted to scores, hundreds or thousands of coins before the problem is repaired. Check out the explanation in From Mint to Mint.

PS: This phenomenon has no relationship to coin ejection.

Smudge

Nice steps.

Aspie_Rocco

@RogerB said:
Mechanical doubling is a product of worn or improperly adjusted equipment. Nearly identical doubling can be imparted to scores, hundreds or thousands of coins before the problem is repaired. Check out the explanation in From Mint to Mint.

PS: This phenomenon has no relationship to coin ejection.

Thank you! I appreciate you checking in. I accept the Question as being answered.

That is an interesting phenomenon with the worn or out of calibration equipment.

So most likely this series of coins over a few years came from the same piece of equipment somewhere in the process. Cool enough for me to keep instead of sending to coin star.

Lots of little die chips in the Philadelphia Jeff’s in 2011-2017. Many P nickels have a chip that alters Liberty to Liborty, due to the cursive font. And in the S of cents.

RogerB

Coin presses were simple mechanical devices and subject to much the same kinds of problems. Another way to think of it is that different presses of the same design could have the same kind of defect, and thus produce mechanical doubling of similar appearance.

The modern Schuler presses in use by the U.S. Mint for several decades are more complex than older Uhlhorn-types but remain subject to repetitive wear patterns.

ricko

Mechanical doubling and you can find excellent descriptions and explanations in Roger's book and other resources. (Just use the search function here on the forum). Cheers, RickO