So this thread is to ask for peoples opinion on this subject. It is in the case of hub doubling/mechanical doubling vs. true double die varieties. In some of the books and magazine that I read, sometimes I come across articles that describe that there is a debate in the collection of hub doubled coins being a legitimate form of error collecting based on the strike characteristics of the true doubled die. What I want to know is what people on this site think about this.
As I understand it, the hub is used to make the die. If the hub is doubled, the die made from that hub will also be doubled, causing the coins struck from that die to be doubled. Mechanical doubling is caused by the die moving as the coins are being struck. Mechanical doubling will be flat and shelf like. On a true doubled die, both images of the devices will appear rounded and have distinct separation. If any of this is wrong, please correct my understanding.
Yes, on the one hand the hub error will only repeat itself once, where the doubled die will repeat itself. As far as hub errors go, there are just as many classifications for them as there are doubled dies,so why not collect them?
All I can add to this, is, pick a coin, lets say like Ike Dollars, hub doubling in the ikes is pretty common, working dies are more rare in this group of coins
All doubled dies are hub doubled. I think you are confusing that with mechanical, or "strike" doubling.
OT: When you say hub doubling, are you referring to the process of the making of the actual working hubs? I know the 1972 cent has a master hub doubling (is that the proper term, master hub doubling? Where the working hubs are made from the master die?)
Oh Yeah, I collect them myself. I have got a couple tubes worth of them, and what I am always doing is looking through them over and over again,hoping that I may have missed something.lol
Master hub>Master dies>Working hubs>working dies The master hub produces master dies, the master dies produce working hubs, the working hubs produce working dies. If a working hub becomes doubled, then ALL the working dies made from that hub will be doubled. If a working die becomes doubled, then the doubling is just confined to the coins struck by that particular die.
I always thought the master die was cut. That's why I was confused with the die process, until now. I knew I was missing a process Thanks guys.
I think thta the master die is the incused image on which it is used to make a working hub. I had gotten a part of my question incorrect,I meant to say strike/machine doubling. strike doubling is done when the coin is struck.
Correct, strike doubling (or machine doubling, mechanical doubling, or a host of other names that describe the same anomaly) is when a die strikes a coin, then bounces up slightly and lands on the coin again; light enough to not leave another strike, but strong enough to flatten part of the design that was already struck.
Rick I think you got it right. A working hub before the single squeeze process was pushed into a working coin die more than once to get a strong impression on the working die. sometimes the die and hub was out of align a little on the second hubbing and this is what created some of the doubles dies that struck the doubled die coins.
same with all this talk about MD, MDD, I go to coin shows a-lot, I've never seen an error expert use thoses words, " ALWAYS " just worn die, thats the cause of anything that's isn't a true double die, so why add all the other names to what the true issue at hand is, and thats " WORN DIE "