Le Cirgue

I am going to deviate from discussion of Goldsmithing and tackle the subject of Gourmet Dining in general and New York restaurant Le Cirgue in particular.  From the outset I am going to state my belief that Le Cirgue has a potential to become a place to visit more than just once.   But for this to take place, they must address quite a few deficiencies in the setup, the service, and the kitchen.

The problems with setup as follows:  Tables are too small.  In fact they are so small that waiters cannot clear table from plates without touching glasses.  And that is an absolute No No in etiquette of table service.

Utensils and plates are mis-matched.  They using plates so huge that utensils appear puny in comparison.  I could not help myself from thinking that I am eating with child sized forks, spoons and etc…  Another thing is that utensil positioning on a plate is a way to communicate with waiting staff of my intentions.  The size of utensils made this impossible because no matter how one positions them, they invariably slide to the center of a plate.

Tables are too close together.  They are so close that there was no room for floor ice bucket.  Bottles of water and wine were placed on our table, taking even more of valuable table real estate.  That made dinner even more uncomfortable, given that table was not large enough to start with.

The service was flawed in quite a few ways as well.  I do not necessarily want to blame it on waiters attitude, although I did notice some laziness on their part.  Most of the problems are the result of the lack of proper training.  They simply do not know how it should be done.  That said, some things were just unforgivable.  Wine service was incompetence on display.

We ordered 2008 Burgundy Gran Cru.  Sommelier arrived with wine carrying bottle under his armpit.  Considering that wine was straight from the cellar, it was too cold to be drunk.  Six years is not enough time for Gran Cru to be ready to drink.  I was aware of that.  However, the situation can be remedied by decanting the wine.  No such attempt has been made or offered.  After I approved the wine, the bottle was unceremoniously placed on our table and that was it.  In my book it was sheer laziness, or incompetence, or both.

Another example of laziness on part of waiting staff was when I dropped my napkin on the floor.  It happen exactly at a time when one of the waiter was passing our table.  I saw that he noticed napkin on the floor.  Our eyes met for a moment but he just went by.  Let me offer my assurance that in any European restaurant the napkin would be replaced instantaneously.  Alas, Le Cirgue waiters do not burden themselves with such details.

Food was hit and miss.  We ordered 6 course tasting menu.  First course was foie gras.  It was not terrible bun neither it was spectacular.  Barely edible at best.  The main problem was that it was prepared by using something known as “meat glue”.  It is widely used in commercial food preparation, but to find it in high class restaurant was simply shocking.  Anyone who ever tried authentic foie gras de torchon would instantly notice the difference.

Second course was yellow fin tuna which was well made and properly spiced.  It was quite enjoyable.  Regretfully, it was also the highlight of our dinner.  From that point on, the things got progressively worse and concluded with atrocious dish of lamb, followed by bland desert and lukewarm cappuccino.   I do not think I am coming back for more.

 

Copenhagen

I have recently visited Copenhagen.  I shot few clips when I was over there.  The first clip was shot in Churchill park and the rest in Copenhagen aquarium.   I still kicking myself for the lack of patience while shooting first clip.  The stork did catch a fish and it would make great transition for the clips to follow.  Alas, one cannot have everything.  My apologies for Google inserting idiotic commercial in videos.  For now I have to use them for my blog.  I hope it is not too distracting.  Enjoy the movie.  

 

Change in DVD distribution policy

I have removed my DVDs from Amazon website, but they are still available on www.createspace.com.     Links can be found on my website www.studioarete.com corresponding pages.  The change should not have any detrimental effect on current and prospective DVD owners.

Regards,

Leonid Surpin.

Why did I quit Orchid

 

I will have to take a trip in a few days.  Should be a week or so.  I might swing by Florida on the way back, but it is hard to predict at this point in time.  Anyway, my mail box is overflowing with “why did you quit orchid” emails.  With my best efforts, I simply do not have the time to answer them all, but on the other hand I do not want anyone to fill ignored.  So I decided to give general explanation here.

Those of you who are members know what took place in the last few days.  And those who are not members probably would not care of it anyway.   So I am not going to dwell on it.  If you do not know what Orchid is – it is a kind of a forum for goldsmiths and others.

The saga which unfolded recently, actually played very little role in my decision to quit.  At best is can be described as proverbial last straw that broke camel’s back.  The decision has been in the works, so to speak, for the last year or so.  With every passing day it became obvious that Orchid is nothing more but an indirect marketing scheme.

The modus operandi is that one of the shills would ask a question, pretending to be someone who is shopping for a product.   Another shill would answer that he/she heard excellent reviews of product X and so it goes.  After couple of iterations, a seemingly reasonable consensus is reached that product X is the  best thing since sliced bread.    And God help a poor soul who would dare to offer a different opinion.   The sky would open and the fire and the brimstone would be pouring on heretic’s head, damming him/her to the farthest corner of Hell, without even a remote chance for salvation.

I simply could not be associated with something like that, because if you are – then there are only two possibilities: either you are a part of the scheme and taking a cut, or you are a dupe who allowed himself to be used to lend credence to the enterprise.  Neither option is something I would entertain to be part of.

That is basically it.  Nothing over-complicated.  I am going to ask something unusual of my readers.  Please do not comment on this article.   Due to my upcoming trip, I would not be even able to review your comments and I do not want to turn this into some kind of a drive to leave Orchid en masse.   This is a personal decision between you and your conscience. Let’s just leave it as that.

All the best.

Leonid Surpin.

Making Of A Goldsmith, Road to Hell Is Paved With Good Intentions!

Sometime old school goldsmiths have to face difficult choices when presented with work which is magnificently bad.  Do you say the truth, or do you make some insipid complement and try to put out of your mind as soon as you can.

The later option is attractive because it is not going to cause any arguments.  After all, there is a lot of ugliness in this world and adding one more item, to compete for the title who is the ugliest, is not going to change much.  From another hand, allowing bad work to stand unchallenged is very detrimental to the Goldsmithing as an entity.  I believe that it is responsibility of mature goldsmiths to be guardians of the Craft and to oppose vigorously all incidents when bad  craftsmanship and/or bad design are been passed as examples of acceptable work.  To that end is the following:

On one of the internet forums ( no need to mention it’s name ) a photos were made available.  Here is one of them

aqua1

I drew some reference lines to illustrate the problems.  Red line is drawn through the center of the bail.  If bail would be attached correctly, the stone and the setting would be divided exactly in the center.  Alas, it is not the case.  This is such an amateur mistake that it is difficult for me to imagine that someone can post a picture with such a defect.  Green lines were drawn along sides of the pendent.  Once again, here is a problem.  Sides must be parallel, but they are not!  Examine yellow lines which underline short flats of this setting.  They are all at different angles, but they all must be at the same angle.  Let’s examine another picture where setting was set already, but without center stone.

aqua2

Setting of the stones only made problems more obvious.  Lack of parallelism, whether horizontal of vertical is obvious.  With center stone removed, the askew factor of the bail been exaggerated.

Add to all of this design deficiencies like dis-proportionality of bail in relation to the setting, poor choice of metal, and etc… This work is lacking in redeeming qualities whatsoever.  However, when pictures were posted on the forum, the chorus of meaningless praises was quite amusing.  Made me think… If I were to skewer some cow excrement on a stick, would the groupies be excited as much ?  One never know, they may like it even more.

In conclusion of this disheartening account on the state of Art of Goldsmithing let me say that the most coveted trait of inspiring goldsmith is critical eye and attention to details.  Without developing these skills, nothing else is possible.  And the first step is to be able to recognize BS under the guise of real work.

P.S.

I was asked to include the finished picture of this pendant under the theory that all irregularities been taken care of by setting the center stone, so here it is:

aqua 3

As you see nothing has changed.  Not a surprise because it never does.  Mistakes done in the beginning, only getting worse as the work progresses.

 

Making Of A Goldsmith, demystifying rolling mill

Rolling mill is a very simple device, that is mechanically speaking.  However, design of a rolling mill to insure ease of use and durability, is a bit involved.  To chose rolling mill intelligently and to be able to troubleshoot problems, a goldsmith should have some understanding of the forces which are involved in rolling of metal.  In this article we shall explore some of these forces to gain better understanding of the process of rolling.

We will use some equations in this text, but set your mind at ease.  I am fully aware of dislike for anything which looks like even remotely mathematical.  So no effort was spared to make it as painless as possible.  Just read the explanations!  The knowledge gained should serve you well when you will  be shopping for your next rolling mill.

Here is schematic of rolling process.

 

Picture 01We have two rolls which are set up with a gap between them.  Rolls are rotating in directions indicated by black arrows.  When metal is fed into the gap, the thickness of the metal is reduced.  Blue arrows indicate force exerted by rolls on metal.  This force, let’s call it useful because we want as much of it as possible ( without putting too much strain on bearings, of course ).  Force indicated by red arrows, let’s call it parasitic, because we do not want at all.  Alas, it is always present, but we should try to make it as small as possible.  Excessive parasitic force can be caused by wrong mill operation, or wrong mill design, or both.  The worst case is when incompetent goldsmith is operating badly designed mill.  Let’s hope that after reading this article you would know how to avoid such situation.

Metal can be deformed homogeneously and non-homogeneously.  The former is the desired outcome.  There is a relation predicting under what conditions rolled metal deformed homogeneously, or otherwise.  If bite ( thickness reduced in one pass ) divided by 2 is larger than roller contact length, the deformation is non-homogeneous.  This relation shows importance of roll contact length, which in turn depends on roll diameter.  The larger roll diameter, the greater roll contact length, and the better chance of homogeneous deformation.  It is not necessary to compute actual length of roll contact.  But if someone wants to know, than here it is:

Picture 02

ac – radius of the roll; bc – radius of the roll – 1/2 bite.  Since abc is a right triangle, then angle c = cos^-1( bc / ac ), and length of roll contact = Cos^-1(bc/ac) * 2 * Pi * radius / 360.  We have to use cos^-1 to convert radians to degrees, Pi is equal to 3.14, 360 is number of degrees in a circle.

Practical example:

Roll diameter is 65 mm.  Bite ( reduction of thickness in one pass ) is 0.1mm.  Then ac is 32.50mm, bc is 32.45 mm, angle C = cos^-1(32.45/32.5) = 3.17 degree, and length of roll contact = 3.17 * 2 * 3.14 * 32.5 / 360 = 1.797mm

As you see contact length is 18 times larger than the bite and deformation will be homogeneous.  It is a fair question to ask “what if contact length is equal or only slightly larger than bite ?”  The answer is that while deformation still will be homogeneous, it would take more power to drive such mill.  The closer we get to the point where bite approaching contact length, the more power it takes to roll the metal.

Another point is that it seems that it would take very small roll diameter or very large bite to create conditions of non-homogeneous deformation.  Well, it is true that for manually operated mills it is largely theoretical, aside of power requirements.  Motorized mills are another matter.  If ingot is not forged prior to rolling, than the first pass should be 1/3 of ingot thickness.  That is where non-homogeneous deformation can manifest itself.  The large first bite is required to change crystalline structure throughout the thickness of an ingot.  But if it is done non-homogeneously, the ingot will be ruined.  The only way to fix it would be to anneal it and forge all over with a hammer.  This is kinds of ironic because first large bite is used to avoid forging.

Ease of rolling, which comes with large diameter rolls, has a price.  Remember force indicated by red arrows, we called it parasitic force.  People who design rolling mills for a living call it Roll Separating Force.  The symbol for it is Pr and equation describing this phenomenon is

Pr = 1.15 * Qp * Gfm * L

It looks a bit intimidating and we can ignore most of it because variables Qp and Gfm are related to width and quality of ingot.  The part that we are interested in is L, which stands for familiar length of roll contact.  From this equation we can see that the larger the length, the greater the roll separating force and mill design must have provisions to deal with it.  Such provisions manifest as massive frame and substantial bearings to withstand increased load.  Adequacy of frame must be considered as it relates to roll width.  As roll width increases, so is the Qp, which is pressure intensification factor per unit of width.  One method of comparing between rolling mills of different design is to divide roll width by weight of the mill.  The one with greater weight per unit of width is probably a better design.  I say probably because mill design is alway a compromise of competing priorities.  If mill will not be pushed to extremes, it is not that important to maximize each and every parameter of mill operation.

Parasitic force can be the cause of roll bending during milling.  It may be difficult to believe that massive steel cylinders can bend, but it is true.  Here is equation describing this phenomenon:

Delta = ( P*L^3 ) / E*I + 0.2( P*L / A*G )

  • Delta is amount of deflection across central axis, which is an indication of roll bending.
  • L is width of rolls here, not length of roll contact.
  • P is roll pressure.
  • E is elastic modulus of steel that rolls are made from.
  • I is the moment of inertia.
  • G is shear modulus of steel that rolls are made from.
  • A is cross-section of the rolls.

We do not need to compute actual Delta to make use of this equation in selecting rolling mill.  Parameter like elastic modulus ( Young modulus) and shear modulus are characteristics of steel and it’s heat treatment.  Moment of inertia describes speed of rolling.  That can be ignored for purposed of comparison, as well as roll pressure.  Mill operator can adjust these parameter.  What is pertinent is A, which is cross-section of roll and L, which width of rolls.  Since A is part of denominator, the larger it is, the smaller the delta, which is highly desirable.  Width of rolls is part of numerator and therefore increases value of delta, which is not desirable.  So we can see that wider rolls require larger cross-section to keep deflection at a minimum.  Cross-section is just another way of indicating roll diameter.  To compare different mill designs we can compute ratio of roll diameter to roll width.  Larger ratio means less deflection and therefore better mill design.

Another phenomenon in rolling is Hitchcook radius.  Hitchcook radius is radius of the roll deformed by rolling pressures.  Such deformation is temporary because it does not exceed limit of elasticity of the roll shape is restored once pressure abates.  Nevertheless, when it is present even in minute quantity, the quality of rolled metal suffers.  Hitchcook radius is denominated by R‘ and equation

R’ = R [ 1 + ( 16 ( 1 – v^2 )) / ( Pi * E * bite )) * Pr ]

Most of parameters should be familiar by now except R which is roll radius when roll is not under pressure, and v which stands for Poisson Ratio.  The only parameters that goldsmith has control over is Pr and E.   E stands for Young modulus and the only way to affected it is to insure that rolls are made from quality steel and properly tempered.  Pr was discussed before and we know that large roll diameter increases it’s value.  Since Pr used as magnifying factor in this equation, large roll diameter increases Hitchcook radius as well.  So, it appears that large roll diameter is positive under some circumstances, but negative under others.  That said, let’s recall that Pr is also dependent on width of ingot been rolled, and on the quality of ingot.  These parameters are under goldsmith control.  So, I would still opt for the largest roll diameter possible and control Hitchcook radius by correctly manipulating ingot.  Excessive Hitchcook radius is the cause of ingot curving either up or down during rolling, and sometime even creates the wave effect.

The last item to consider is torque, which is denominated by M and expressed by equation

M = Pr * L / 2

where L is length of roll contact, and Pr is roll separating force.  All these parameter quite familiar by now.  So there is no need to rehash it.  However, subject of torque brings attention to reduction gears and length of handle.  Torque of any mill can be increased by lengthening it’s handle.  However it is not recommended, because by doing so you can exceed load specification for bearings.  Length of the handle can be used as an indicator of magnitude of stress that bearings can take.  There is another aspect to reducing gears and length of handle.  Very frequently mill manufacture has several models in different roll width.  While extend of forces in mills of different width are remarkably different, all mills are equipped with the same gear ratios and the same handles.  I understand that it is easier that way, but from the point of design it is absurd.   I would seriously question commitment to quality by such manufactures.  But if you have no choice but to deal with one, select the mill in mid-range.  Chances are that such mill would have the best characteristics.

We have come to the end of this article.  If you feel a bit disappointed, I can understand that.  After all, the title is “Demystifying Rolling Mill”, but after re-reading it myself, I feel that mystery only got deeper.  Look at it this way.  There are no perfect mills because there are no perfect materials.  No matter how well chosen steel is and how well tempered, it is still a subject to deformation with all it’s consequences.  I do hope that you would approach selection of rolling mill and it’s operation with more attention to details and better understanding of the process.

Leonid Surpin

 © 2013, Leonid Surpin, all right reserved.