The difference between hub doubling and Machine Doubling. Note the curved devices and ask yourself: Does the affected areas look enlarged or reduced. Note on the affected devices, those areas are reduced on these devices. There are doubled dies on this area of devices, but what to look for on them? They are called class 2 doubled dies:

Now lets look at some of these to see what to look for:



On these doubled dies the spread can be at the top or bottom of the devices. depending on the doubling whether towards the rim or towards the center of the hub on the creation of the die. What can cause this? having a different hub during the creation of the die. A different hub state, or the hub was damaged/worn when being used to complete the run that day. To us we view the dies created as a single one at a time. But hundreds of dies are completed. Also keep in mind before the single squeeze dies, the hub process took more than one process to create a die. The die would be softened, and the hub applied and the die would rest. This would happen several times usually 3 times. Larger coins even more. So the hub could be worn/aging/distorted/warped/damaged during this process. Maybe a new hub would be introduced. So the different hub state, could create a doubled die and not even factoring in an alignment issue. So on these images, take a look at the affected areas? Do you see the area near the rim show notches, widen base of the devices enlarged curve on this area. On the coin above, note the Machine Doubling is showing a reduction of these devices. So I'm going to show more examples of these as these are minor ones. What do the major ones look like?






While the next one looks like Machine Doubling, note that the devices are taller:

Compare to these machine doubled examples below. Note the affected areas are flat, reduced even smaller than normal devices:




Note how the Machine Doubling reduces the devices?
So here are a few more images to show the class 2 hub doubling. While minor, they are examples on 1962 proof cents:







Hope this helps. I've got a whole lot more images to post. Just helping to train the eyes on what to look for on doubled dies and how Machine Doubling is a reduction of the devices.

Now lets look at some of these to see what to look for:



On these doubled dies the spread can be at the top or bottom of the devices. depending on the doubling whether towards the rim or towards the center of the hub on the creation of the die. What can cause this? having a different hub during the creation of the die. A different hub state, or the hub was damaged/worn when being used to complete the run that day. To us we view the dies created as a single one at a time. But hundreds of dies are completed. Also keep in mind before the single squeeze dies, the hub process took more than one process to create a die. The die would be softened, and the hub applied and the die would rest. This would happen several times usually 3 times. Larger coins even more. So the hub could be worn/aging/distorted/warped/damaged during this process. Maybe a new hub would be introduced. So the different hub state, could create a doubled die and not even factoring in an alignment issue. So on these images, take a look at the affected areas? Do you see the area near the rim show notches, widen base of the devices enlarged curve on this area. On the coin above, note the Machine Doubling is showing a reduction of these devices. So I'm going to show more examples of these as these are minor ones. What do the major ones look like?






While the next one looks like Machine Doubling, note that the devices are taller:

Compare to these machine doubled examples below. Note the affected areas are flat, reduced even smaller than normal devices:




Note how the Machine Doubling reduces the devices?
So here are a few more images to show the class 2 hub doubling. While minor, they are examples on 1962 proof cents:







Hope this helps. I've got a whole lot more images to post. Just helping to train the eyes on what to look for on doubled dies and how Machine Doubling is a reduction of the devices.
Edited by coop
05/08/2020 8:57 pm
05/08/2020 8:57 pm




















