1932-s Quarter RPM?

[JamesWiles]

There are several ways for MDD to happen. The most common appears to be from worn bearings which causes the die to twist when it comes under pressure from the strike. Usually this causes MDD on several areas of the coins. Another mechanism for MDD is the ejection process. The coin sticks to the reverse die and when the ejection fingers push it off there is a shearing or bounce which gives the doubled image. This is particulary true with washington quarters. Apparantly the way the die is set into the press in relation to the feeder fingers causes the mintmark to be the last area to release and thus receive the twisting of MDD. It almost always occurs on the east side of the mintmark and is very common on all dates/mints with the mintmark on the reverse of the coin.
The mint does NOT repair damaged dies. Once a die is determined to be unusable it is discarded. Repunching occurs with the mintmark is initially punched into the die and the punch bounces or isn't deep enough and has to have a second blow from the mallet.

[billscoins]

1932-s Rpm?

Thank you James. I'm always interested in learning about coins. The how something happens is interesting to discover. I am a little confused as how this coin was created. Several questions are developing which I know you have an answer for, plus I know , everyone as they learn about this manufacturing process, ask you the same Questions. Please bear with me, I'll try not toask questions without research before hand. Thanks, Bill

[Speedy]

I do not see a crack with 7x.

These die cracks are always light, so yours might have worn to where it can't be seen. If I can get the photos to work I have many that I could upload.

I will post my photos as I go along. I am discovering more questions about this coin. You seem like the man who has been on this road for a while I hope you will not mind some inquirerys about your experiences? Thanks for your input. Bill

Keep the photos coming---I love to look at different coins with the same look.
The die crack and other markers seem to match the DDR that Mr Wiles lists in his book on Washington Quarters.

Usually this causes MDD on several areas of the coins.

And that is why I find this coin interesting---I have checked out as many of these as I can and I can't find any other MDD on any other part of the coin. It also just doesn't have the look that the other MDD mintmarks that I have seen do.

[billscoins]

1932-s RPM?

My experience in die making does not rule out MDD but it also leaves a question in my mind as to other possible causes. I have seen simialar problems in metal working where things like this are caused by a combination of factors which are hard to isolate until a marker of each factor has been indentified. I know we can not form conclusions about this coin until I can formuate questions based on the info the pictures can answer for us. Your experiences with other coins will be most helpful and thank you in advance for any uploads you may send.

Thanks, Bill

[diamond]

If it's any help, I've encountered quite a few silver Washington quarters with machine doubling restricted to the D- or S-mintmark. Exactly how such specificity occurs has never been entirely clear to me. Usually it's attributed to the mintmark having higher relief than other design elements, but this really doesn't account for those that show a very low shelf that occupies a level well below much of the rest of the design.

Sometimes you just gotta accept some mysteries.

[billscoins]

1932-s RPM?

"Sometimes you just gotta accept some mysteries."
I love mysteries. This one fits my background and interests. Thanks for your input maybe we can issulate the factors which have caused this one and run this rabbit to ground. I wonder if you or someone else knows about the following:
In my reading of the die making process, I have noted the hub die is often made without the mint mark and the mint mark is punched in the master die at the mint by hand. A working hub(with mint mark) is then made and then the dies are made from this hub with the mint mark.
Or:
The Master Hub is made with the mint mark and is then used to make the dies.
Does anyone know what method was used in 1932?

Thanks, Bill

[wavysteps]

From 1990 to the present, all mint marks are applied to the master die (punched in). Before that date, mint marks were applied (punched) to the working dies. This accounted for the wide variances in the positions of the mint marks before 1990 and no variance of positioning of the mint mark, from working die to working die, after 1989.

Thus, in 1932, the mint mark would have been applied to that working die and the position unique to just that one die

BJ Neff

[diamond]

Up until 1990, the mintmark was punched into each working die by hand.

[billscoins]

1932-s RPM?

Well, I believe a little study of the pictures is in order.
(The pictures are from a comparator where the coin is tilted to the axis of the lens and after correcting for mirror image and hue.) The image is 50x and has a field of view only 1/4 the thickness of the letter thus each area in question has to have it's own picture so it will be in focus.
Observations:
1. The fourth picture clearly shows doubling ( none other is present on the coin).
2.The third picture shows a crushed lower half of the top serif.
2 possible causes:1. broken punch in this aera, 2. filled die cavity in this area, & 3. ?
3. The first picture shows a square shaped hole at the top with what looks like some fill at the bottom.
2 possible causes:1. broken punch in this aera, 2. filled die cavity in this area,& 3. ?
4. Also, all features seem to be above the fields surface with the doubled surface lower than the mint mark.
2 possible causes:1. the first hit not deep enough with second hit on the punch deeper, 2. The coin moved relative to the die only in the area of the mint mark.- 2 possible causes:

1. The machine bounced,top die shifted with coin setting in collar and the top die moving(mint mark side) enough to cause a .005 in. ledge .003 high only in the areas shown. THIS IS A DOWNWARD FORCE SINCE THE LOWER STRIKE HAS TO BE FISRT(THE OTHER SETS ON TOP) the die must then shift and then the full mint mark has to be struck last. ( My experience says that would place unequal forces on the die edges which could cause them to crack on the sides which shear .) plus leave traces of doubing elsewhere. ( No traces)
2. The ejection fingers pushed the coin accross the mint mark die side in such a way to cause the ledge to be formed as shown in the pictures(A SHEARING ACTION).-might be possible if collar is moved away and mint mark is higher than surrounding features on sheared side. The edge of the mint mark on the coin could catch on the edge of the die and shear a ledge as it pops out of the die (looks like surrounding features are higher than mint mark - some of them should catch first.)
So what have I left out?
1. Its a soddered on mint mark. ( 3 experts from NGC do not think so.)
or a factor which no one in the coin or the die-making industry has pointed out as of yet.

If anyone sees some other possibility, please point it out. I love a good mystery. Thanks for your help, Bill

[billscoins]

1932-s RPM?

More questions after a little research (& you know what they say about a little knowledge.)

We all know, when a coin is produced a mintmark is formed by pressing a blank into die (relatively speaking). Metal must flow into the CAVITY from the flat surface of the blank. This cold forming of the metal causes a stretching and work hardening of the metal in varying amounts in relation to the degree of deformation. With enough magnification we should see areas on the coin (around the edges of the mint mark) where the metal flows into the cavity. This should show up as small, stretched, tares because of the work hardening of the metal while forming the shape. The metal on the coin will flow into the larger areas ( requiring the least force) first and into then the deeper areas last (requiring more force). The more force applied to the metal the more evidence of work hardening ( or cold forming) should show.
I am now in the process of researching how this metal flow should look (and how to show evidence of my findings). In the following 2 cases, machine doubling & RPM.
So far, I have only seen one style of mintmark and think that the same punch may have been used on all the 1932-s dies.
Please take a look at the picture from speedy’s thread RPM? Which is attached. If we visualize the inverse of this picture to represent the punch ( without the doubling) used on all the dies, the pictures of later die state coins may tell us something from the metal flow patterns we see. Next to speedy’s picture are three pictures of my coin. As you can see mine is a later die state and has more wear (NGC X45).

Has anyone seen an example where another punch was used on the 1932-s?
Still researching, Bill

[billscoins]

1932-s RPM or MDD

After a little more research I think I have an answer which may support Mr. Wiles hypothesis of Machine Damage Doubling (MDD) from a form of EJECTION doubling.

I have increased the magnification used to 30x with a loupe and have noticed what appears to be; 1. A piece of metal from the bottom serif is pushed up onto the top of the letter, & 2. Another piece pushed over from the top serif to the top of the letter.

I want to reduce this case to two possibilities and to see which case my observations support. 1. Strike doubling, which I’ll define as caused by a downward force from the press. & 2. Ejection doubling which I’ll define as a shearing force caused as the coin is forced out of the die after forming.

In this case a shearing force may have caused the deformation of the Mintmark as the coin was pushed out of the die by the ejection fingers. The metal seems to be pushed up onto the top of the letter in two places. Also I see some cracks in the form of the letter, which may have been formed when a shearing force was applied to the side of the letter.

If any one has a picture of the mintmark without deformation, it would help me show through a series of pictures how this condition could have developed. Thanks, Bill

[diamond]

Ejection doubling, machine doubling, and strike doubling all refer to the same phenomenon. It's caused by movement of the die relative to the coin, or the coin relative to the die, immediately after the initial impact of the hammer die. Two forms of machine doubling are recognized -- "push doubling", which produces marginal shelving and "slide doubling", which produces smearing of the design. Intermediate forms also exist. Here's more information:

http://www.minterrornews.com/news-1-30-07-doubling.html

[billscoins]

1932-s Rpm?

Thanks Mike, for the reference article. I find in trouble-shooting machine problems, that associating deviations to applied forces allows me work my way back to the machine elements, which caused the problem. It helps to see the categories, which you have developed in order to explain mint errors. Without a clear understanding of an error it is often every difficult to isolate the cause (or causes). Your approach of giving names to observed deviations is very helpful, as you name your categories in relation to the possible causes based on your experiences.

Using my understanding of your category “sliding Doubling”, this coin could have been formed by a shearing force pushing the coin across the die face as the coin popped out of the die just as the pressure was released on the upstroke (with the coin released on the opposite side of the doubling first). This explains the metal buildup on the surface of the mintmark. However, since no other features seem to be affected I believe at least one more factor is involved. I believe MDD is the most likely cause of the doubling, it only remains to explain, the shearing forces application to the mintmark only.

Any thoughts as to how this is possible?
Thanks, Bill

[diamond]

In many cases it's difficult to pinpoint the cause of the shear. It could be the hammer die moving sideways after the lowest point of its downstroke is reached. It could be the coin being pushed sideways by a mistimed ejection finger before the hammer die has had the opportunity to retract. It has always puzzled me how machine doubling can affect an isolated design element like a mintmark, but leave no trace elsewhere. Some folks relate it to the relatively high relief of the mintmark, but this doesn't address those cases where shear occurs very low on the mintmark. I've learned to live with a good many mysteries.

[wavysteps]

Not to confuse matters, but there are other forms of design extra thickness that many associate with machine damage doubling and they are not.

One example of this can be found on the 1982 (LD) Lincoln cent with extra thickness seen as ramping, especially on the letters of LIBERTY. Since this occurs on all the large dated 1982 Lincoln cent (both copper and zinc), this must have occurred during the hubbing process (while making the master die) and not the striking process. As to the cause of this extra thickness, I am not to sure, however, it maybe due to the affect that I have outlined below.

In my studies of the anomalies called trails and wavy steps, I have also encountered another form of extra thickness (that I categorize as design extension) caused by movement of the die against the hub at the end of the hubbing process. At times, instead of just a high point on the hub, a leading edge of a design element on the hub will be drug across the die giving the appearance of extra thickness of that design element. One way to identify such extensions is the absence or continuation of flow lines (from the surrounding field) into the extra thickness. I have a 1997P Lincoln cent die that shows this type of extra thickness very well in the word LIBERTY, with some of the affect showing in IN GOD WE TRUST as well.

Just wanted to add to the information on this very informative post.

BJ Neff