Machine Doubling

Talk low, talk slow, and don't say too much...

LOL!!

I will have to read everything again, to understand it a little better, but I think I might be starting to interpret it a little better.

 

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Frank how about an update on Longacre doubling , as I've read about it but still don't have it down stone cold .
rzage

 

T$:
I'll do that next.
Rzage:
Yes, That'll be shortly! (Longacre Doubling).

Thanks to all for comments, and nominations.

 

Here is a picture of a DDO, (note: NOT machine doubling)

Note the fact that the two images are the same height, and both are rounded.



This was a roll search find.

 

But what about that coin makes it a Doubled Die, rather than machine doubling.

 

Here's a couple of examples for T$. The first one is doubled die and the other machine doubling.

ddo

md

 

I think T$ is asking what a hub doubled die is, how its made, why it happens, and what are its characteristics. Once you understand what it is and how its made, seeing the difference becomes much easier.

I would explain it all right now, but my sister is having her 13th birthday/slumber party tonight, so we're going crazy getting everything ready. Oh goody, 6 screaming 13 year old girls - just what I always wanted.

 

T$,
I'll go into that in the next segment.

Very soon.
Frank

 

Okay now that helps, I think simply studying those pics, I might understand a little better..
Thanks everybody
I will read those links again as well

 

T$, if you look at the DDO the primary letters have retained their size where-as the letters of a machine doubling will have been reduced in their original size. Make sense?

 

Treashunt
taking a shot in the dark here, Is tha a '72?

Richard

 

Doubled die is an imperfection in the working die whose attributes are transferred into the design elements of the coin when struck. Machine doubling transfers an imperfection onto the coin due to a mechanical problem with the strike itself.

A doubled die can be traced to a problem in the manufacturing process of the die.
Machine doubling can only be traced to a problem in the manufacturing process of the coin.

 

Richard:
Nice shot!

Excellent guess.

Good job.

And, yes.

 

Frank , great thread , I new the hows and whys of machine doubling , but didn't always have the examples down cold , now I do . This Thread should go in the archives for learning .
Rusty

 

There are two types of machine doubling, "push doubling" and "slide doubling". Push doubling creates shelving at the margin of the design and rounded doubling on interior portions of the design. It's caused by a die bouncing, shifting position slightly, and landing lightly on the newly struck design. Slide doubling smears the design and pushes metal up in a series of ridges. It's caused by a die that shifts laterally after reaching the lowest point of the downstroke.

Machine doubling can be caused by die instability, press vibration, a loose cam, a coin that sticks to the anvil die, a mistimed feeder finger, a mistimed retraction phase of the hammer die, etc. A loose die is probably the most common cause.

I consider machine doubling a mint error. Alan Herbert declared the minting process to be over as soon as the hammer die reaches its lowest point. This was an arbitrary (and I think ridiculous) cut-off. Any press malfunction that creates well-separated doubling shiould be considered a mint error.

While minor examples of machine doubling are common and worthless, extreme examples are rare, eye-catching, and worth quite a bit. I've seen strongly doubled Sac dollars (two sets of eyes, lips, noses, etc.) bring prices in excess of $80, even when they were accurately described as machine doubling.

 

I will agree with you on that Mike I also think they are ,machine doubling I have very extreme ones which i can see with the naked eye.

So technical they are considered an error I think that;s great, because all this time I thought they weren't thanks for making my day

. I have many with extreme doubling on them which will probably bring a nice premium on them

Unfortunitly the extreme die deterioration coins i have are not an error because it;s just normal die wear.


Thanks Mike

Jazzcoins Joe

 

Here again, there are exceptions. Normal die wear is not an error; abnormal die wear and die distortion IS an error. Die wear/deformation that is premature, localized, and unusually severe or peculiar is indicative of a problem in the die steel.

 

Very interesting terms in die wear

I wish you could show me an example of these different forms I would like to see the differance on each termonology So I could notice what you are talking about on a coin, so I can distingush what is an error or not Could you possible furnish a web site for this ?

Thanks Joe:bigeyes:

 

Congrats on Thread of the Week, you earned it.

 

Thank you, [takes modest bow!]