Leonids casting challenge

Jewelry Discussion
1

was: Legal definition of hand made

The progress thus far is that I've managed to make the channel
section of the ring, and due to lack of experience I haven't found
the best way to make the fish tail section. I'm taking the channel
section directly to the casting house tomorrow to see if I can
figure out the conversion issues (it may come down to the fact that
I may have to buy a student copy of Rhino).

More on this:-

I took my model into the casting house and sat with the designer.

The channel section looked fine, but upon further inspection there
were a couple of voids, so it would not have made a successful wax
print.

It was suggested that I get an.stl repair tool to make my models
water tight (their terminology). I’ve downloaded an application and
will see if this works.

Apart from the voids the channel section looked fine.

I also confirmed about stone setting, and finish, this is not a
problem, however the comment was made that polishing inside the
channels would be a royal pain.

I’ll keep you all posted.
Regards Charles A.

2 
The progress thus far is that I've managed to make the channel
section of the ring, and due to lack of experience I haven't found
the best way to make the fish tail section. I'm taking the channel
section directly to the casting house tomorrow to see if I can
figure out the conversion issues (it may come down to the fact that
I may have to buy a student copy of Rhino).

Some people get upset when distinction is made between handmade and
otherwise made jewellery, but there is a significant difference.

The experiment referred to above is precisely to the point. When one
reads complete Charle’s post, it is fascinating how much high tech is
involved in trying to come close to something that very easily done
with traditional techniques. And the ring is not even that
complicated.

There are things that computers can do much better than humans, but
goldsmithing is not one of them. Traditional goldsmithing requires
creative thinking, which computers are not capable of yet. The
jewellery thus produced is different and there are segment of the
market willing to pay for that difference, and therefore the legal
restriction.

I want to end by citing an example from Computer Science. There is a
long standing problem in Computer Science known as “Traveling
Salesman Problem”. It involves calculating the most efficient route
for a salesman to take if he has to visit multiple towns on his
trip. (google it for better description)

A number of ways to solve this problem was developed, but as number
of nodes (towns) increases, even the most powerful computers are
brought to their knees. This is due to combinatorial explosion of
possible routes to consider.

What is interesting about this problem is that it has a very simple
solution without use of computers. If one inserts pins in a map
marking location of towns and connect pins with threads - it will
create a set of all the possible routes. To find the most efficient
one - simply take starting node in one hand and ending in another.
Spread arms appart, stretching network until straight line forms
between starting and ending nodes. This straight line is the most
efficient route through network.

Traditional goldsmithing is very much the same way.

Leonid Surpin

3

Leonid and Charles,

I wouldn’t take the challenge, not that it couldn’t be made by CAD
or any other technology. The trick part of this is…“strength”. In the
world of casting vs. forged or handmade rolled metal the cross
section under microscope would bring a sponge look in the casting
and a more solid effect in the compressed forged or rolled metal.
Mere tumbling will not produce the strength you can get from rolled
metal. In other words, the molecules are stronger in a rolled plate
than in a cast plate. So let’s hear the comments on this…

Russ

4

Hi Guys,

Personally I’m not upset about the distinction, for me at the end of
the day it’s about creating jewellery, by any means high tech, low
tech or experimental.

The course I’m currently doing is a trade jewellery manufacture
course. Fine jewellery, but the key word is “manufacture”. The market
for pieces made in such a manner are for everyone.

The designer course, is for designer jewellery, and this jewellery
is definitely not affordable for the masses.

The difficulty I am experiencing is due to my inexperience, a half
way proficient CAD designer would be able to make do Leonid’s
challenge in about an hour (less with more experience), cast an
finished the next day. Also with this is a global body of work in the
form of image libraries, where designing a ring is a matter of cut
and paste. I’m also using a 3D program that is designed for making
blockbuster movies, not for jewellery CAD/CAM. If I was less stubborn
I’d be using the same software as the casting house.

The technology I was looking at the other day will produce an item
with dead straight lines, exact channels, exactly repeated shapes and
perfect curves, to 16 microns accuracy. This is not able to be done
by hand. Added to this 16 microns is the start, the definition will
only get better as the technology improves. There are just some
things that machines can do that we cannot. Consistent, tireless,
perfect accuracy is where machines win. Ask Gary Kasperov.

While I was with the CAD/CAM man at the casting house I watched him
designing a ring, it was absolutely mathematically perfect. If he
didn’t like something, he’d simply change it, no re-working metal.
Was it beautiful, definitely, could that design be done by hand sure.
Were there things that could not be done by hand, yes.

I can see that when I figure out my problems the final ring, it will
will be inhumanly flawless in appearance, it will polish (I’m
assured that it will take a high polish… yet to see this), and it
will take stones. What was confirmed is that the ring will not be
work hardened.

Is there a thing as “too perfect”? I think this is what will happen
with the ring upon completion. I have here in my house two Japanese
swords from WWII, one is a NCO’s sword which is machined, and one is
a 16th century blade with a Naval officers fittings. The NCO’s sword
is perfectly machined, and is beautiful in it’s execution. The
commissioned officers sword is hand forged, and is as perfect as a
hand can make, but in that, the human failings is what gives it
character over the machined sword.

Regards Charles A.

5

Russ nails it! To merely do an exact reproduction misses the critical
element. And that is one would preferably improve the performance of
the piece by certain ‘tricks’. A few of us touched on this the first
time around. Of course though, for that to have any meaning we’d have
to know the real world performance of the original ring. Got to
remember jewelry is worn, not just displayed on a webpage.

6 
Russ nails it! To merely do an exact reproduction misses the
critical element. And that is one would preferably improve the
performance of the piece by certain 'tricks'. A few of us touched
on this the first time around. Of course though, for that to have
any meaning we'd have to know the real world performance of the
original ring. Got to remember jewelry is worn, not just displayed
on a webpage.

An interesting development, I’ve sent some questions to people that
do something really high tech with metals.

It might solve the durability of the castings… maybe. I’m not
going to give the game away yet, as I may be able to come to an
arrangement with the boffins.

Regards Charles A.