1840 rouble with awesome die polish

[WCO]

Here are some more thoughts on the issue: No matter how Bolton press worked I still think that upper die could have an ability to rotate by by 2-5 degrees (plus or minus). One out of many reasons is that a die may become loose and there is no need to dig deep into mechanics of press to understand that. Speaking about "friction of the planchet against the dies" friction is not a force, it can't move anything by itself, especially large quantities of metal. There must be a force. And friction unable to change direction of movement of large quantities of metal (assuming that friction is constant), there must be another force. If you remove a die from press and lay it down on a planshet there will be friction (friction at rest). But there will be no coin struck, no metal moved. For that you need force. About molecular friction, I think it is not molecular level (may be I am wrong, then correct me), metal was moved in large quantities, laws other than on molecular level are in force here.

 

regards,

WCO

[squirrel]

Think of it like putting a piece of wood into a bench vise. You turn the handle and squeeze the vise, The handle goes around and around, but the vice only squeezes the wood, the vice jaws do not turn.

[Hussulo]

Squirrel got it. It's "The Art and Craft of Coinmaking; A History of Minting Technology" by Denis Cooper. Denis is a former Chief Engineer of the Royal Mint. After retiring he formed a firm specializing in minting equipment. I had the good fortune of personal contact w/ Denis in the early 1990s. He's very sharp on minting tech and a wealth of info. His book is THE reference for thos interested in historical minting technology. It's out of print but you can occassionally find copes on eBay or ABE Books.

 

Thank you.

[RW Julian]

Thank you.

I obtained my copy from Charles Davis (a Massachusetts book dealer,

specializing in numismatics) in 1994 and he no doubt has a copy from

time to time for sale.

 

It is a book well worth owning for anyone interested in the technical end

of coinage.

 

RWJ

[mummytrol]

I get a little dizzy looking at the eagle:

 

1840 rouble

 

Now I know that pre-1844 roubles were technically not struck as well as later coins, and that they used a die until it fell apart. I have some Russian coins with similar die cracks. But what would cause the swirly shape of the letters? Is this also due to die polish and/or wear? Has anyone seen anything like this before?

Hello, People! Maybe all of this coins just a bunch of fakes. Take the look at the rims. Thks. M.

[gxseries]

mummytrol, if you are talking about the excessive "cud" on the edges, it's actually rather common on coins from that era.

 

Here is another example:

 

 

edit: And guys, negative/unrelated personal comments are subjected to be removed / deleted and maybe warned. Negative comments are not very helpful to anyone here so please kindly be thoughtful to others. I personally don't want to do this but will if it keeps going at this rate. Thanks

[mummytrol]

mummytrol, if you are talking about the excessive "cud" on the edges, it's actually rather common on coins from that era.

 

Here is another example:

 

 

edit: And guys, negative/unrelated personal comments are subjected to be removed / deleted and maybe warned. Negative comments are not very helpful to anyone here so please kindly be thoughtful to others. I personally don't want to do this but will if it keeps going at this rate. Thanks

I ment letters oh the edge. In that 1842 rouble what picture i put before they are not straight. Thank you. M.

[bobh]

I ment letters oh the edge. In that 1842 rouble what picture i put before they are not straight. Thank you. M.

But none of the edge lettering is visible in the picture you supplied...so what do you really mean???

[mummytrol]

But none of the edge lettering is visible in the picture you supplied...so what do you really mean???

I will try to do a picture. M.

[rittenhouse]

Here are some more thoughts on the issue: No matter how Bolton press worked I still think that upper die could have an ability to rotate by 2-5 degrees (plus or minus). One out of many reasons is that a die may become loose and there is no need to dig deep into mechanics of press to understand that. Speaking about "friction of the planchet against the dies" friction is not a force, it can't move anything by itself, especially large quantities of metal. There must be a force. And friction unable to change direction of movement of large quantities of metal (assuming that friction is constant), there must be another force. If you remove a die from press and lay it down on a planshet there will be friction (friction at rest). But there will be no coin struck, no metal moved. For that you need force. About molecular friction, I think it is not molecular level (may be I am wrong, then correct me), metal was moved in large quantities, laws other than on molecular level are in force here.

 

WCO,

 

Since you have stated that you do not know how the presses functioned, what you "think" is invalid. It is an axiom of logic that one cannot argue from a point of ignorance. I will state again: The design of all presses, including Boulton's, is such that the dies do not rotate with striking. Squirell had an excellent analogy with his example of a vice. The slide mechanism is such that it effectively isolates the movable jaw from the torque. Screw presses are even more torque isolated since even the slightest rotation during strike would have disastrous shearing effects on the appearance of the devices. It it not necessary to take my word on this, anyone can easily check by getting a copy of Cooper or a few mechanical texts.

 

And, as I previously pointed out, even if the dies were loose in the die cups, as soon as the strike begins the loading effectively locks the dies in place for the remainder of the strike. As with press design, you do not need to take my word on this. There are many, many coins out there that are "rotated die errors". If the dies continued to rotate during the strike, these pieces would show shear effects on the devices. Since they do not, the empirical evidence is that the dies lock under load. If this is insuffcient, one need merely consult with the engineers from a private or public mint.

 

Further, the science of Physics does recognize friction as a force. Again, it is not necessary to take my word on this. Just look it up in wiki. In fact, here's the link: http://en.wikipedia.org/wiki/Friction. If you're suspicious of wiki, you can google it and find many, many refs from major universities saying the same. If you distrust that, you can simply order a decent text.

 

If you wish more information on the internal frictional and structural forces affecting the deformation of metal you can simply consult the appropriate metallurgical texts. The "Metals Handbook" I mentioned previously is a great place to start. You do need a fair understanding of mechanics and physics, though.

 

I believe that fully covers this subject unless others would like me to expand (within the limitatons of a BBS) on some technical point.

[rittenhouse]

And guys, negative/unrelated personal comments are subjected to be removed / deleted and maybe warned. Negative comments are not very helpful to anyone here so please kindly be thoughtful to others. I personally don't want to do this but will if it keeps going at this rate. Thanks

 

My apologies gx. I became irritated at WCO's smart-mouthing. Usually I find this sort of thing amusing, but this time it caught me. I'll do better in the future.

[moneydog]

Those are nice coins. I like the Russian double eagle.

[WCO]

Rittenhouse,

 

Since you gave me wiki to read about friction, may I also use an article from the same source that is a bit more advanced than the article you gave:

 

http://en.wikipedia.org/wiki/Coefficient_of_friction

 

In that article it states that "It is important to note that in all cases, Newton's first law of motion holds". In ALL cases, in gases, liquids or moving particles of metal under pressure, in all and any objects. You told me that I "forgot FRICTION" but you did not explain what friction has to do with our discussion and how it may impact the ever holding "first law of motion".

 

May be I was not clear but under "force" I meant "external force", not friction as force. What prevents movement of metal inside blank is internal friction. Friction acts in direction against movement, and external force can change direction of movement.

 

We can endlessly engage into this and dig too deep. However, here is one point. You are not trying to explain the phenomenon but rather trying to criticize my theory here and there. By doing this we moved far away from the initial discussion. So far we only agreed that it most likely has nothing to do with die polishing.

 

Many rubles struck before the middle of 1840's had more or less the same look with crude flows of metal visible on the surface with naked eye, however just some of them had "curls" of metal and others had linear (straight) flows of metal. Once Boulton presses were removed from mint in 1845-1846 (and may be some other changes to technology) the quality of Rubles improved and there were no more coins with heavy flows of metal on the surface. So I guess everyone was expecting from you an answer to a question, what was "defect" in technology that sometimes produced "curly" patterns of metal on a coin. We are not talking about single Ruble, we are talking about quantities of both kinds of rubles, even though kind with linear flows of metal found more often. I provided my own "theory" of what happened, from the beginning stated that it is "questionable", you criticized my theory, fine I can live with that. Now it is your turn to tell your vision of issue. You only gave the info that "... twist... was probably caused by the misalignment of the dies (note the heavier strike at the dentils on left), the dies wear/damage, possibly combined with a poorly annealed planchet". Both kinds of coins with linear and curly patterns could have more weakness in strike in one "corner" of a coin and heavier strike in another "corner" of the same side. So at least a relation of die alignment to the form of those patterns is not that obvious, explanation is necessary. Dies wear/damage would mean that ALL next coins produced by this die should have about the same curls, since they also would be struck by the same worn/damaged die. Please provide more info how wear and what kind of wear of a die may result in "twists" of metal we are discussing.

 

I will appretiate if you will be able to also answer the following questions: 1. Should be there a difference (or there may be no difference) in external forces to produce curls of metal versus linear flows of metal? 2. What may be a source of such "additional" forces then (if any)? 3. What exactly resulted in such a pattern of metal on a coin and what was different from coins with linear flows of metal?

 

regards,

WCO

[Bill Snyder]

WCO - The mention of rotation of Boulton presses (dies) brought this English cartwheel to mind:

 

 

 

I hope this is relavent to the discussion.

 

 

Bill

[WCO]

WCO - The mention of rotation of Boulton presses (dies) brought this English cartwheel to mind:

 

 

I hope this is relavent to the discussion.

Bill

 

Bill, thank you.

 

Interesting and unusual example, for sure it is relevant here. Unfortunately, pictures are not that good so I am not sure what kind of error it is. If it is a double strike than it proves only that die could rotate between two strikes, however rittenhouse insists that same kind of rotation is not possible during single strike, i.e. not possible to strike coin with twisting (rotational) move of a falling die. I do not know mechanics of a press so unable to check elements that would allow (or prevent from) this kind of move or something that would result in such a move, I have to trust rittenhouse expertise here. All I know is that plastic flow of metal in those coins (with curly flows) for some reason was different than in other "normal" coins (with linear flows) and I want to find the cause.

-------------------

 

On PCGS web-site I found definition for "flow lines": http://www.pcgs.com/lingo.chtml?Letter=F

 

flow lines - The lines, sometimes visible, resulting from the metal flowing outward from the center of a planchet as it is struck.

---------------------

So linear (straight) metal flow lines where "metal flowing outward from the center" are common, it is what one expects to see on a coin. Curved (twisted, curly) flow lines are unusual. Plastic deformation of metal there went differently than on other similar coins for some reason and I want to find out why.

 

WCO

[rittenhouse]

You only gave the info that "... twist... was probably caused by the misalignment of the dies (note the heavier strike at the dentils on left), the dies wear/damage, possibly combined with a poorly annealed planchet". Both kinds of coins with linear and curly patterns could have more weakness in strike in one "corner" of a coin and heavier strike in another "corner" of the same side. So at least a relation of die alignment to the form of those patterns is not that obvious, explanation is necessary. Dies wear/damage would mean that ALL next coins produced by this die should have about the same curls, since they also would be struck by the same worn/damaged die. Please provide more info how wear and what kind of wear of a die may result in "twists" of metal we are discussing.

 

I will appretiate if you will be able to also answer the following questions: 1. Should be there a difference (or there may be no difference) in external forces to produce curls of metal versus linear flows of metal? 2. What may be a source of such "additional" forces then (if any)? 3. What exactly resulted in such a pattern of metal on a coin and what was different from coins with linear flows of metal?

 

regards,

WCO

 

WCO,

 

OK, I now understand what you're trying to get at. The answer is quite simple, but I doubt you're going to like it. Here it is anyway: UNKNOWABLE.

 

The problem is we have nothing to analyse. Oh yes, we have a PHOTO of a coin showing odd flow artifacts, but that's all we have. In order to fully analyse the effect we would need the original press, the original dies and the original planchets. The problem with engineering failures is that they are exceedingly complex. There are usually several competing forces and cascading effects. Very difficult to analyse. The I35W bridge collapse is a good example. It's been 4 months and they still haven't settled on the root causes. And they have the bridge, the cars and a video! We have nothing.

 

Absent the ability to fully analyse all the contributing factors the only thing we can do is iterate the general causes of this type of defect and postulate based on the photo. I attempted to do that in my initial post. Perhaps I wasn't clear. Let me expand:

 

1. Flow lines are caused by the movement of metal. Metal will flow away from point of highest pressure.

2. Due to variation in the dies (high and low points), curvature of the dies and devices cut into the die, there are many points of high and low pressure across the surface. Thus the planchet metal may or may not flow in the idealized "radial pattern".

3. Die wear, cracks and buckling of dies alter the die shape and thus the flow.

4. Position, size, depth and direction of the devices will affect the flow.

5. Strike pressure affects the flow.

6. Planchet hardness affects the flow.

7. Parallelism of the dies affects the flow.

8. Frictional forces affect the flow.

 

 

We also know that heavy flow lines of this type are seen in low pressure strikes or late state coins with very worn and degraded dies. The dies in this example are late state and quite worn and degraded. We can also see that the dies are out of parallel. This led me to postulate that the twisting lines were caused by the misalignment of the dies and the die wear, possibly combined with a poorly annealed planchet.

 

I did forget to add one thing though. Documents in the Boulton archives show that Boulton's engineers were critical of how the Russians made the dies. They felt the die forgers and engravers did not follow the best practices and made relatively poor dies. So, we can add this as a possbile cause. However, we should see evidence of that on earlier state examples.

 

Anyway, there's your answer. Beyond this point the only thing you can try is to come up with the original dies and the press, or at least a reaonable full-scale reproduction of such, and run experiments. Of course you could just accept that you know the generalities and leave it at that. That's what I do. Figure it out to a point of reasonable knowing. Otherwise you're just gonna work yourself into a tizzy over nothing knowable. No thanks. Me? I'm gonna go play some golf.

 

BTW, you said: "do not know mechanics of a press so unable to check elements that would allow (or prevent from) this kind of move or something that would result in such a move, I have to trust rittenhouse expertise here." Actually you don't. I rarely ever make a statement without providing easily checked references. Just get the books. If you can't find Cooper, Boulton's engineering drawings were also published in the 1815 American Edition of the New Edinbugh Encyclopedia. In sum, the info is out there, all you gotta do is look.

[WCO]

That's the easy answer: UNKNOWABLE. You should say it from the beginning, strange only that you are pretty sure that it may be anything but not a complex movement of a die under more than one force. I though that may be there was a research for similarly looking coins, not necessarily Russian (with non linear flows of metal) and you are aware of it.

 

Anyway, thank you for your time and replies and pls. forgive me if you found something wrong in my posts.

 

Regards,

WCO

[rittenhouse]

That's the easy answer: UNKNOWABLE. You should say it from the beginning, strange only that you are pretty sure that it may be anything but not a complex movement of a die under more than one force. I though that may be there was a research for similarly looking coins, not necessarily Russian (with non linear flows of metal) and you are aware of it.

 

Anyway, thank you for your time and replies and pls. forgive me if you found something wrong in my posts.

 

Regards,

WCO

 

Your post indicates that you still don't get it. The cause(s) can not be known with the SPECIFICITY you desire. That is, we cannot state that Y and Z caused a pressure gradient of X in this area which in turn caused the curving flow lines. However, we can know what does and does not cause flow lines within the general parameters of coining by screw press. That is what I said in the beginning.