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25c 2012 Double Die

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Valued Member

Canada
125 Posts
 Posted 02/18/2015  11:31 pm Show Profile   Bookmark this topic Add numidan to your friends list Get a Link to this Message
I saw this one was not posted on this site. I suspect that the 2014 is similar to this one.

This coin has class 2 doubling. The doubling is stronger on the elements at the outer rim and non existent at its center. All pictures were taken with the same lighting and same magnification(except for the montage at the end).






Valued Member
Canada
125 Posts
 Posted 02/20/2015  07:37 am  Show Profile   Bookmark this reply Add numidan to your friends list Get a Link to this Reply
Here is the nobody wanted to publish article that I wrote int 2012 for this coin:

Single-Squeeze Hubbing Class 2 Doubling

The Canadian mint has recently released the 2012 caribou quarters. Having found some of these in my change last week, I decided to observe them under my digital microscope in hope of finding errors. I was very surprised to find one with doubling. At first I thought it was Mechanical Doubling but soon realized that it may actually be hub doubling.

Examining every details of the coin to find characteristics of hub doubling, I proceeded in ruling out Die Deterioration by comparing the apex of the relieves with a normal coin and examining the location of the doubling. The result of this work is shown in figures 1 to 3.

The surprising part was the fact that this doubling was not centralized as you would expect with single-squeeze hubbing. In fact, it has the characteristics of class 2 doubling. The doubling is stronger on the elements at the outer rim and non existent at its center. Figure 4 illustrates the doubling existing all around the coin. I believe the unusual expansion rate due to the annealing of the steel rod, used for the working die, is the reason of this type of doubling.

Therefore, I am quite certain that this coin has class 2 doubling and unless the Canadian mint recently changed its hubbing process, it was produced using single-squeeze hubbing. The exact population is not known, so keep an eye out for this coin!
Valued Member
Canada
402 Posts
 Posted 02/20/2015  10:43 am  Show Profile   Bookmark this reply Add SelectCoinCanada to your friends list Get a Link to this Reply
Have you found any more since you wrote this article in 2012?
Valued Member
Canada
125 Posts
 Posted 02/20/2015  11:53 am  Show Profile   Bookmark this reply Add numidan to your friends list Get a Link to this Reply

Quote:
Have you found any more since you wrote this article in 2012?


Hi fed_ink85, I found 6 in circulation since then.
Valued Member
Canada
125 Posts
 Posted 02/21/2015  07:44 am  Show Profile   Bookmark this reply Add numidan to your friends list Get a Link to this Reply
I thought this coin would have stirred some interest, comments, criticism, debate, etc.

Upon reflection, I think I may have offended the community last week and I am sorry.

I am very passionate about double die. I have read every article I was able to get my hands on. I wanted to figure out how they are formed and what they look like. Since I do not own a coining press, I used the next best thing to experiment, Play-doh and plastic molds. I soon came to the conclusion that there maybe a flaw in the primary evaluation criteria that people use to differentiate MDDe and WDD. For the last 3 years I have written 3 unpublished articles, replied to posts, developed software to help evaluate errors (CoinExpert), drew illustrations and assembled montage to get people to question them selves on the topic, but in vain.

Last week, I had an occasion to get a pillar of the community, SPP, (which I respect a lot by the way) to question himself. I was convinced, by using supporting arguments, I would get him to see my point. I may have come on too strong and when I felt that he was not interested, I lost it and I regret that.

My sincere apology.
Pillar of the Community
Canada
2632 Posts
 Posted 02/21/2015  11:23 am  Show Profile   Bookmark this reply Add Alexer to your friends list Get a Link to this Reply
Its all a lack of knowledge..For the record this has peeked my interest, the U.S. forum is posting possible DDs daily but not so much here. The whole thing with U.S double die's is they are listed on several sites with the markers plainly photographed but again not so much here. Collectors can open up a couple windows on the computer and hunt DDs all day long there.

Do you have a blog site with your unpublished work? You could have the link attached to your forum name and we all could refer to it when need be. Follow your passion and we will follow too, give us info and pics and bring it on.
Thanks for bring this DD to my attention I will be watching for it.
Pillar of the Community
Canada
2422 Posts
 Posted 02/21/2015  4:38 pm  Show Profile   Bookmark this reply Add Altaira to your friends list Get a Link to this Reply
I second pennyman. I don't reply if I think what I write may be wrong, misleading, or adds to the confusion.

This one is definitely confusing me. Outward doubling is often Die Deterioration Doubling, but I'm not sure with your coin.
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Pillar of the Community
Canada
1713 Posts
 Posted 02/21/2015  9:11 pm  Show Profile   Bookmark this reply Add rocky to your friends list Get a Link to this Reply
hello numidan. I would like to say to you like your article. I also have a question. why do you say this so I can understand .I believe the unusual expansion rate due to the annealing of the steel rod, used for the working die, is the reason of this type of doubling. does the mint heat this rod for a reason and why thank you just like to know
Valued Member
Canada
125 Posts
 Posted 02/22/2015  09:00 am  Show Profile   Bookmark this reply Add numidan to your friends list Get a Link to this Reply
Hi Rocky,

This is how I see it. As the press pushes down on the hub into the die blank, normally the metal will flow outward, expanding the die blank outwards (top image step 3). When it completes its run, the die blank has properly expanded and is now a working die. In the case of class 2 doubling, I hypothesize the metal is not flowing outwards properly. This will allow the hub edges to prematurely make contact with the blank (bottom image step 3). As it completes its run, the die blank continues to expand (bottom image step 4). In step 5 is now a working die with class 2 doubling.



Below are the pictures I took with the digital microscope. In the first picture, I compare a normal coin with the doubled coin. You should see that the doubling is outward toward the rim for both the bead and A. Thus, the hub must of made contact before the metal fully expanded. In the second picture, I tried to compare the difference in size of the doubling. The doubling of the bead is a bit longer than the doubling of the A, supporting the fact that it did not fully expand before contact. The last 2 pictures are those that I took to create the montages and for others to experiment.









P.S. At the time, I did not know that there were no annealing in single squeeze process and it was using cold forging. You can only learn by exposing yourself and making mistakes!
Edited by numidan
02/22/2015 09:08 am
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Canada
8916 Posts
 Posted 02/22/2015  12:36 pm  Show Profile   Check SPP-Ottawa's eBay Listings Bookmark this reply Add SPP-Ottawa to your friends list Get a Link to this Reply
You need to account in your model the following:

- the hub produces a matrix (master die) which then in turn, creates the working dies. This is not through a squeeze process, but a punch. That is why you'll never read Haxby writing about hubbing, he refers to such features as punch doubling. Tooling marks and such are usually from touch-ups on the matrix, since the dies are (now) titanium coated (and were chrome plated with older dies).

- the matrix is slightly concave, which results in working dies that are slightly convex, which facilitates the high speed strikes and ejection of the coins.
"Research is what I am doing, when I don't know what I am doing" --Wernher von Braun

Content of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_US

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Pillar of the Community
Canada
1713 Posts
 Posted 02/22/2015  12:45 pm  Show Profile   Bookmark this reply Add rocky to your friends list Get a Link to this Reply
numidan thank you very much very well done and explained. you see. this is like a puzzle . I would like to say to you and Ottawa spp that you are both right. I am amazed at the work all the members do here. to help educate us all . the annealing process is part of the problem and so is the plating . double struck and triple struck is also the other part. and I know what the cause is. I will say 3 things and when I do there is member that are going to know right away. I would like for them to fill in the spaces. if not I will tell you and all the members how come there is Machine Doubling and tripling. it has to do with a term called a cycle and a steel ball baring and a spring. right know a lot of members know why the doubling. for a single push press. if no one comments in 2 days I will explain then you will understand why you and Ottawa spp are both right. I hope someone else that understands the tern answers
Valued Member
Canada
301 Posts
 Posted 02/22/2015  1:40 pm  Show Profile   Bookmark this reply Add abderrahim to your friends list Get a Link to this Reply
Hi all, I add new pic for this 25 cent 2012, I think that is DDO,











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Canada
8916 Posts
 Posted 02/22/2015  9:35 pm  Show Profile   Check SPP-Ottawa's eBay Listings Bookmark this reply Add SPP-Ottawa to your friends list Get a Link to this Reply
Actually... I got the order mixed up in my post above, and it is slightly more complicated. The processes described here are for Canadian coins:

You can either get a reduction matrix (incused like a die) or a reduction punch (raised features like a coin). That punch is then used to sink a matrix, at which time features are added (last digit of a date for example) - I suspect modern coins are created from a reduction punch and the matrix that results from that is complete, because of computer production. So you get one matrix, per denomination, per year. In turn, each matrix creates multiple punches. Each punch is annealed, and the edges are ground off, and then those punches are used to sink the working dies - it is last stage, that creates doubled dies...
"Research is what I am doing, when I don't know what I am doing" --Wernher von Braun

Content of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_US

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Valued Member
Canada
125 Posts
 Posted 02/23/2015  11:02 am  Show Profile   Bookmark this reply Add numidan to your friends list Get a Link to this Reply
SPP, thank you for rectifying your original post. Any input is appreciated.

I will take the liberty to add to your statement;
"it is last stage, that creates a rarer form of doubled dies..."

Don't forget the 2006 Canadian nickel where the double die was formed at the production of the master die. Thus, all working dies were doubled dies.


Quote:
term called a cycle and a steel ball baring and a spring.


Hi rocky, I've googled in hope to find where this is going and found nothing. I am curious and will be waiting for further denouement.

Hi abderrahim, glad to see another member has found this coin. Thank you for the pictures.
Pillar of the Community
Canada
1713 Posts
 Posted 02/24/2015  6:45 pm  Show Profile   Bookmark this reply Add rocky to your friends list Get a Link to this Reply
ok a little back ground.the biggest press I have worked on was and H press 50 tons from 1974 to 2013. hydraulic jacks of 100 tons when you numidam and Ottawa spp . was posting on the other topic posted by castor. pennyman007 hit the press right on he said straight forward but he is very right in his account of pressing. todays hydraulic pumps are either 12 piston or 24 or bigger. these piston drive the hydraulic fluid which pushes the pistons in the coin press. ok so one cycle we will use 12 piston think for one moment a tractor pto turns 540 RPM in a minute so that would mean the pump pushes 6840 time per minute.one cycle is 12on the pump if you reverse the spline the pto turns 1080 turns per minute for a total of 12960 pumps this is todays rotary pumps. on a electric motor it is even faster at idle.so here what ties you and Ottawa spp together if the pressure release value. which is a steel ball bearing and a very expenses steel spring say the fluid had a little used or what ever in one one thousand a coin can get hit 2 - 3 4 times before the value opens and there a many causes plus the mint could set it so it does strike more than once. when you talked about the annealing process. if the blankes are not heated they would shatter apond being struck. the annealing does 2 thing softens the metal plus expands it as well . a railroard track on a hot days grows through the day and shrinks at night. asd do pipe line that's why they have expansion joints. the blanket are not all the same temperature that would be impossible that explains the different field you members talk about. and the diffent oddity on the coin. and imagine the mint has a high tex camera that doesnot allow these coin out.it finds them and recycles them so to find one is great. I have worked with press and jacks all my life.it is what I have done for aliving. I could go on you memebers are great people very smart and I respect you all. I see that collecting is for you as much for me a passion remember we learn every day something new hope I did not bourght you have a great one and keep looking who knows what next great find is out there
Pillar of the Community
Canada
1713 Posts
 Posted 02/25/2015  10:51 am  Show Profile   Bookmark this reply Add rocky to your friends list Get a Link to this Reply
thank you numidam. I want to share with you. I am new to coin collecting. I have collected over the years quit a few coins and just put the stuff away . my father was the collector as well as my son. my father purchased some of his collection from a dealer. I think he is here on this forum. he would show the coins and the receipts. my dad always spoke highly of this dealer. I have my dads collection I bought it plus 2 other collections from other older collectors. I have retired and want to learn as much as I can. I can see I am at the right spot.my career was with working with metals and electric. lots of pressing and hydraulic. so this is a little about me. I hope the members don't mind me asking for help but I have some very nice coins. I need to do some thing with these collections. my father told me always do your homework when it comes to coins thank you.
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