Triple MDD? Typical

[bigbawbo]

I believe that this is MDD, is tripling like this common?

[diamond]

You can indeed find tripled, and even quadrupled examples of machine doubling. It doesn't happen all that often, but it's by no means a great rarity.

[ROB EZERMAN]

You can indeed find tripled, and even quadrupled examples of machine doubling. It doesn't happen all that often, but it's by no means a great rarity.

Mike, care to comment on the mechanism of this triple MDD?

I find this MDD simply amazing, great pictures! Rob

[ROB EZERMAN]

Follow-up Triple MDD cent

I believe that this is MDD, is tripling like this common?

bigbawbo, could you please identify this cent by year and mintmark? Is there any doubling or tripling on the reverse? Is there any MDD distortion of the inner obverse rim? THANKS! Rob Ezerman

[Novicetoerr]

Multiple MDD ...1960 cent >4x doublings

Hello and just FYI,

Have posted in Page 3 of 16 (Die Variety Coin Forum) a coin with multiple
(not letters ,but nose/eyelid) MDDs.


Regards,
NVTEs

[diamond]

Mike, care to comment on the mechanism of this triple MDD?

I find this MDD simply amazing, great pictures! Rob

For unidirectional tripling and quadrupling of the image, one supposes that jitter in the die or press will be sufficient. What stumps me are those more exotic cases in which:

1. Machine doubling is present on both faces (either in the same direction or different directions).
2. Machine doubling is in two directions, one offset and one rotational.
3. Machine doubling is in three directions. I have one nickel with machine doubling south-to-north, west-to-east, and east-to-west. Don't ask me to explain it -- I can't.

[ROB EZERMAN]

PUSH MDD

Mike, thanks, agree except there is a whole lot more going on in MDD than I understand let alone explain. This cent, for example, appears to have a shelf off the end of the R's right leg (our right).

The perfectly shaped uniformly flat twin shelfs to me imply a fairly powerful double "push" from the obverse die while the coin was still seated on the reverse die and I'm still having trouble picturing this kind of powerful bounce unless the receeding hammer arm moves at just a bit more speed or earlier departure than the anvil die rises such that the spacing between receeding hammer die face and obverse coin face remains quite close: then it would seem possible that un-damped up and down rapid elastic movements in the hammer die mechanism could cause the hammer die to come back down on the coin one or more times creating "push" MDD.

It would be fun to examine this cent to see if the MDD is consistent with push MDD.

Sorry to persist (perseverate?) trying to visualize the creation of MDD, just what I have to do. Rob