Double Die Question?

Non-mechanical DD errors? Lose that terminology and conceive of it in this way. In Machine Doubling, a.k.a., Strike Doubling, the doubled image is formed as a consequence of the striking of the planchet by the dies into the coin. The planchet slipped or hopped or twisted a little when it was struck. The collar couldn't hold it still, for whatever reason. Contrast that with die doubling. Die doubling is on the die, itself. It's imparted from the die to the planchet. It's an error. Strike Doubling isn't an error. Die doubling typically happens at the hubbing stage, but we shan't get into that. Here's where you want to be. This lays out pretty clearly how the traditional ones as well as the modern ones happen, as they are different...

https://www.doubleddie.com/58222.html

I don't know what 1955 D doubled die you are speaking of so lets go with the major 1955 doubled die. This doubled die was created when the die and hub were misaligned from the first squeeze after the die returned from being annealed. (before 1997 dies required multiple squeezes of the hub and die withthe die being anealed or softened between each squeeze.)

In the case of the 1955 DDO the misalignment was from a rotation around the center point of the die. Not you say that Lincoln does not show doubling, but this is not true if you look clocely you will find the bust is doubled as well. But since the rotation is at the center you will find that the further you get from that center point the more extreme the doubling becomes. Lincoln is much closer to the center than IN GOD WE TRUST is so the doubling is much less prominent on the bust than on the motto. You will note the the LI of LIBERTY shows greater separation than the TY because the TY is closer to the center of the rotation.

On the 1995 the rotation or pivot point was located around the date of the coin so the 1995 date shows very little doubling. but on the opposite side of the coin the farthest from the pivot point you see much greater separtation on LIBERTY

Here is the chain of command on how the hub/dies are created:


So a doubled die (referred to as the working die) is doubled from the working hub. The master hub is at the top of the list. Created from the design. (different than the setup used today I'm pretty sure) But the master hub is the start of the chain, then two master dies are created, that create many working hubs and the working hubs create many, many dies. Issues multiply when you have a doubled working hub several dies could be created from doubling on this level. But with a master gets doubled, half of the coinage of that denomination could be affected. (1972 master die issue) The 1955 is a class one die issue:






One the doubled dies that affected the front of the face areas:


CoopHome : Master hubs/dies and the 1955 DDO-001 how affected?

This is fascinating. I've read various articles on the hubbing/die making process. It seems that while the U.S. Mint is trying to eliminate doubled dies and die errors, they might still be using old technology. I would have imagined the Mint would use high precision CMM (accuracy in microns), CAD and five axis CNC machines to produce working dies. Am I missing something? Is it the artist/sculptor who needs to fine tune the model? Is it too costly to modernize? Or is it something else I'm missing?