Author Topic: Die making sequence  (Read 2386 times)

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Offline Pabitra

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Die making sequence
« on: April 07, 2013, 11:01:07 AM »
Usually only one large plaster cast is made and then suitable sized master dies are made, if more than one denominatin commem coins are to be issued.

I have noticed that a coin on Bal Gangadhar Tilak was issued with two dies.

Here are the images.

In India, honorific titles tend to get permanently attached to the name. for example, 80 percent of present generation in India will not be able to recognize Mohandas Gandhi unless they are told that it is same as Mahatma Gandhi.
Prefix titles are more common but suffix title "ji" enjoys same status as "Esq." in England.

In case of this coin, the prefix honorific title, "Lokmanya" was acceptable but "ji" was not acceptable.
Hence the coin wwas withdrawn after the release  function and issued without "ji".

Since the plaster cast had already been made, the additional word was scraped out as is clearly visible on higher denomination coin.

However, from what it appears in the image, the coin of lower denomination was made from a new plaster cast.

Can one educate me as to what could have been the conditions/ constraints/ requirements which led to making of a fresh plaster cast, if it did?

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Pabitra
« Last Edit: November 21, 2013, 05:34:33 PM by <k> »

Offline Figleaf

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Re: Die making sequence
« Reply #1 on: April 07, 2013, 02:20:47 PM »
You cannot just take a character off a legend of a machine-struck coin. It disturbs the balance of the coin. On traditionally designed coins, the beginning and the end of the text is positioned in such a way that if you draw a straight line between them, it will be exactly horizontal compared to the lowest point of the coin. I often make use of this when preparing a picture for the forum in order to make sure the coin or token is presented in the right position.

In addition, the space between characters is set, just as the space between words. In other words, delete or add one character and you have to do the whole legend again. In the computer age, it is faster and cheaper to do a new plaster. This will also give you the opportunity to work on small flaws that became apparent only after striking started.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline Pabitra

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Re: Die making sequence
« Reply #2 on: April 07, 2013, 10:53:35 PM »
Lest you get a feeling that I took of a character from a coin using any image processing software, let me inform you that this unbalanced text coin appears to have been issued as a part of proof set by India.

The same image can be seen at various places like

http://kulraj-the-numismatist.blogspot.be/2010/08/proof-set-150th-birth-anniversary-of.html

http://en.numista.com/catalogue/pieces36221.mobile.html

&

http://rajesh-godofkings.blogspot.be/2012/04/100-rupee-indian-commemorative-coins.html


I have no interst in proof sets of any country but it must be a unique coin with unbalanced text. It becomes even more conspicous since you know that a new plaster cast and die was made to correct this error on 5 Rupees coin.

Incidentally, it was reported to me as a unique coin and I did the final search.

You could shift it to unique type coins.

Offline Figleaf

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Re: Die making sequence
« Reply #3 on: April 07, 2013, 11:34:58 PM »
Yes, hard to interpret. If the proofs were struck later than the circulation coins, it could mean that the mint doesn't care about its coin collecting customers. If the proofs appeared before the circulation coins, it could mean that the mint loves its collecting customers (or at least their money) so much it could not accept any delay for the proofs ;)

It's not unique, though. European coins of the 16th and 17th century abound with mangled legends.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline dheer

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Re: Die making sequence
« Reply #4 on: April 08, 2013, 05:37:26 AM »
There is a plaster cast, from this one makes a "Mother Hub" - This is positive image, looks like coin, releif.
From this there are one or more "Master Dies" - This is -Ve image, incuse
From the Master Dies, there are one or more "Working Hubs".
From the Working Hubs, one creates the Working Dies.

On Circulation strikes or of lower denomination, as the number of dies required is large, always working dies are used.
In large denomination coins, since the number of dies required are less, one typically use the Master Die.

Now on Tilak high value coins, my GUESS is that the Mother Hub & Master dies for high denomination were already made. Instead of throwing these away, dies are expensive, the mint MAY have modified the Mother Hub or Master dies by removing the extra chars.

However on the lower denomination as they number of dies required are anyways large, starting from new plaster is relative less expensive as the cost is distribued over ..
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Offline Figleaf

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Re: Die making sequence
« Reply #5 on: April 08, 2013, 09:52:39 AM »
Sorry, dheer. That reasoning doesn't work. The same plaster is used for making proof and circulation dies, so if you make a new plaster for the circulation coins anyway, you may as well use it for the proof dies also.

Cost is hardly an issue. When using the plaster, the only difference is that the reduction lathe is set at a different size for the proof die. Making a new master for the proofs will cost time, as the lathe is slow, but it is not costly. The marginal cost of using the machine approaches zero, the machine can work unattended, it just needs setting. The resulting die also needs hardening and polishing, which is also not back-breakingly expensive, especially in view of the ridiculous margin collectors will pay for proofs...

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Offline dheer

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Re: Die making sequence
« Reply #6 on: April 08, 2013, 09:57:09 AM »
Peter,
I though the reduction lathe takes few hours ... but I see your point it may not necessarily be a cost & time issue in true sense ...
... then maybe the mints are just lazy  :)
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Offline Pabitra

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Re: Die making sequence
« Reply #7 on: April 10, 2013, 12:29:20 PM »
It's not unique, though. European coins of the 16th and 17th century abound with mangled legends.

is it fair to compare 21st Century with 16th or 17th century technology or environment?

There is a plaster cast, from this one makes a "Mother Hub" - This is positive image, looks like coin, releif.
Now on Tilak high value coins, my GUESS is that the Mother Hub & Master dies for high denomination were already made. Instead of throwing these away, dies are expensive, the mint MAY have modified the Mother Hub or Master dies by removing the extra chars.
However on the lower denomination as they number of dies required are anyways large, starting from new plaster is relative less expensive as the cost is distribued over ..

For what I know, there is one plaster cast only.
From lower value coin of Tilak, it is understood that a fresh plaster cast was made.
Why the same was not used for high value coin?

Yes, hard to interpret. If the proofs were struck later than the circulation coins, it could mean that the mint doesn't care about its coin collecting customers.

The proof came after the controversial release, since the correction, as required was done.

... then maybe the mints are just lazy  :)


Yes. Either the mint does not care about anything ( not only  its coin collecting customers) or they are lazy or ignorant or (what Indians call) " Chalta hai " attitude.