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Cab calibration problems


#1

I’ve joined an artist’s co-op and they’ve been pushing me to get my
stuff into the store (they really like the stuff I wear, but its all
I’ve got from the Old Days right now, I’m still buying tools and
supplies!)

So I went ahead and did something I’ve never done before, I bought
some pre-made bezel settings with posts and some small round cabs to
make simple stud earrings (and a few other odds and ends of stuff
that can be thrown together quickly with no soldering required).

Well, the cabs I bought - 4 mm and 6 mm - don’t always fit in their
same-sized bezel settings. about 3/4 of the 4 mm are too large, and
about half of the 6 mm.

Is this a problem with ALL smaller cabs, or just this one supplier?
There was no warning about calibration problems in their literature,
which I have seen before with other suppliers.

It does appear to be a problem with the stones and not the settings.
The stones that are too large are too large for ANY of the settings.

Sojourner
Ottist Annoyedatus


#2

Dear Zen,

This is one of the problems I have had as a small manufacturer. I get
around this with faceted stones by buying the machine cut stones then
testing them out prior to full blow production. Cabs are a different
problem and harder to produce with. I think the whole thing is that
stone cutters don’t set and setters don’t cut stone.

I never have been able to buy a 4mm stone and a 4mm mount and have
the two fit together as is. I always test first and have ,of course,
learned the hard way by making a one of which I design to produce,
costing it out, making the one only to find that I need to either
buy 3 different sizes of stones and mounts to match up or taking the
chance that I will be able to repeatedly get the same sizes of each
which will fit. The former has never happened and I have priced out
pieces only to find I can’t get what need at the price I thought I
could.

This lesson has taught me to be patient with the production process
and let it take the time it takes even if my clients don’t understand
why I can’t just make the piece. I often use commissions to produce
the prototype for a production piece. This lengthens the time it
takes me to make the commission because of the stated problems and
lord have mercy if I get stuck, then I am forced to get the
commission done and worry about the production designs on my own
time. For cabs I have found the only way to produce a quality product
is to make bezels to fit each stone. I can work up a length of a
particular gauge to cut for a certain size of stone but have found no
way to actually have that fit each stone and quality suffers.

I find bezel cups are too thin and to hard to set because they are
sterling ( I always use fine silver for bezels) and look like crap
because they are die struck and somewhere along the perimeter of that
bezel there is a crinkle.

I found that I can only use bezel cups in very few instances where
price is the main criteria.

Sam Patania, Tucson
www.patanias.com


#3
    I found that I can only use bezel cups in very few instances
where price is the main criteria. 

I have never used manufactured bezels before, nor have I ever tried
to use such small cabs. Frankly, I’m not interested in trying any
more of the 4 mm cabs even if they DID fit into the bezels.

I was doing this in the interest of speed - trying to get enough
stuff fabricated so that I can have at least a few things on display
by next month. Even at 6 mm, I really feel like its not worth the
time and effort to make bezels by hand.

If I can’t rely on getting calibrated stones, I’ll have to drop this
line altogether. I can’t imagine what I’d do with handfulls of tiny
little cabs that wouldn’t fit into the pre-manufactured bezel
settings they’re supposed to go with.

Is there any particular supplier you’ve found that was better than
others?

Now I’m worried that the oval cabs I bought are going to be useless,
too. Sheesh, no wonder its so hard for people to find simple stud
earrings, if we have to custom make bezel settings for them it just
isn’t worthwhile to fabricate them by hand!

Sojourner


#4

Hello Zen & Sam,

Sterling bezel cups are frustrating, but the fine silver bezel cups
are quite nice. I bought a selection from Rio when the first came
out… MUCH better than the sterling cups!

Judy in Kansas, who had fresh strawberries for supper… the turtles
had their fill first though.


#5

Where did the cabs come from?

Craig
www.creativecutgems.com


#6

I don’t know about smaller sizes, but I have ordered many 8 x 10
oval cabs, and even some facetted stones that size, from Rio, and
never had a calibration problem. I order that size because I’ve
designed an earring style around the only safe and appropriate (for
my design) cinch mount they carry–and it only comes in 8 x 10. The
jump rings on the mount are a little wonky, but it always fits the
stones perfectly, and I frame it with wire and spirals so the
wonkiness doesn’t show.

The only bezel setting I’ve ever done has involved fine silver wire
and solder. Maybe someday I’ll get to do that again…

Lisa Orlando
Aphrodite’s Ornaments


#7

Dear Zen, did you see Judy Willingham’s suggestion about the fine
silver bezelcups from Rio?

I havn’t tried them myself and as soon as I get my Rio bill paid I
will order some. Other than that I have found a subcontractor who I
have make such items for me. They make and set the bezels for $3
each my cost with the post soldered on. They have interesting order
times and I have to be very specific about the item I want. I send
them my stones. THis is the only way I can get this type of earring
done, they sell very well and I’ll be damned if I can get myself to
make them even if I have bezel cups. These guys do make all the
bezels by hand and fit them to the stones, they do very good work.If
you want the contact let me know.

Sam Patania, Tucson
www.patanias.com


#8

As a stone cutter, I find this discussion quite interesting. Let me
be so bold as to suggest that it seems what folks are talking about
here is not really making something, but assembling finished
products from other people’s manufactured work. I’m also going to
suggest that, while, as has been stated in this thread, there is a
problem with stone cutters and metal workers not understanding each
other’s work. But a far larger problem is that the people who are
buying these products are looking for the lowest price they can get
as a primary criterion. I suspect that customers for these products
could easily get exactly what they wanted were they willing to pay
the price for that accuracy. Here’s why in terms of stone cutting.

It’s the last part of cutting and polishing a stone that takes by
far the most time. The tolerances you’re talking about here are
probably in the range of 1/4 of a mm or less. The calibration time
and polish is probably about 1/2 of the time spent on cutting. Cut
it too small and you can throw it away. The eye is very acute in
seeing something out of round or even out of oval. So when you’re
cutting this stuff, it has to be done very very accurately. If it’s
not cut quite right, every time you scratch up the surface of a
stone, you have to go through usually at least 5 separate steps to
get it back to polish again. And when you go through these steps you
have to estimate how much you’re going to lose to make sure it’s not
going to be too small. It simply all takes time to do both well and
accurately.

And what’s the seller about with 4mm and 6mm material? Dumping it
on the market as quickly as possible. Often you the user are buying
it for pennies a piece and getting it from some of the poorest
countries in the world whether it’s hand or machine cut. Most
American cutters cannot possibly compete with that labor market so
we don’t. The people who are doing the cutting are being paid
practically nothing, by our standards, and they’re probably being
paid by quantity produced not quality of the product. Truthfully, a
4mm stone takes nearly as much time to cut as a 12mm stone and is
truly a pain to work with in that size. I wouldn’t be surprise if
1/3 are wasted.

I have little doubt that the pre-made setting that you are buying is
produced in a similar way. At least metal, however, can be more
easily machine made because it is a much more consistent and
predictable material than stone.

All of this is to say, you get what you pay for. If you want to pay
what accurate cutting is worth, I’m sure you can find well
calibrated stones. The truth is too, adjusting your stones to fit
you settings is not that hard.

Derek Levin
www.gemmaker.com


#9

I, too, bought a bunch of stamped bezel cups in the beginning
thinking they would be easier. I found out pretty quickly that the
stones vary, but the stamped cups do not. Turns out to be easier to
make my own bezel cups.

I don’t know what to do with the handful of stamped cups now,
though. Seems a shame to put them in the scrap bin!


#10
    Where did the cabs come from? 

Thunderbird.

And they STILL haven’t gotten back to me about this or other problems
I had with the order. This would be the third time I’ve had trouble
getting a response from them (as in they never respond unless I
manage to actually catch someon in person on the phone).

They LOOK ok, there are just way too many of them that are the wrong
size, far too large to go into the pre-made settings they sell.

I called Rio Grande and they tell me all their cabs are calibrated
within a very fine tolerance of the stated size. I’ll try them.
Thunderbird’s non-response alone is enough to tell me its risky
doing business with them. It took me a couple of hours to untangle
the strands of beads and pearls I ordered from them. The quality
looks ok, but the calibration problem with their cabs and the fact
that I can’t seem to scare up a response from them means I won’t be
doing much business with them in the future.

Sojourner


#11
    As a stone cutter, I find this discussion quite interesting.
Let me be so bold as to suggest that it seems what folks are
talking about here is not really making something, but assembling
finished products from other people's manufactured work. 

The manufactured products that I’m assembling are machine made.

I’m not sure what point you’re trying to make as far as “assembling
finished products from other people’s manufactured work”. I have a
stated request from customers for simple stud earrings and a need to
get some work onto the shelf at my artist’s co-op fast, so I went
the bezel setting (complete with ear stud) and cab route to get
there.

I'm also going to suggest that, while, as has been stated in this
thread, there is a problem with stone cutters and metal workers not
understanding each other's work. 

I don’t see where this comes into this situation at all. I’ve
bought cabs that are stated to be a certain size. They are NOT that
size, and do not fit into the settings sold by the same retailer. The
problem is with calibration. The stones being sold are not within a
reasonable tolerance of the stated size. If they were, half or more
of them would NOT be failing to fit into their corresponding
pre-manufactured settings.

But a far larger problem is that the people who are buying these
products are looking for the lowest price they can get as a primary
criterion. I suspect that customers for these products could easily
get exactly what they wanted were they willing to pay the price for
that accuracy. 

Undoubtedly. However, I assumed that by buying from a large,
well-known, and I presumed RELIABLE seller, I would be able to be
pretty sure that the stones they sell me allegedly calibrated to 6 mm
would be within a reasonable tolerance of 6 mm. I don’t CARE how much
they lose polishing, grinding, or whatever. I want a 6 mm round cab
that fits into the 6 mm pre-made earring stud setting that is being
sold to me by the same supplier.

If they can’t do that, I won’t buy from them anymore. I would like to
find out from others who they have bought from in the past that they
were able to get stones that were actually the size they ordered, eg
were calibrated correctly. Just trying to cut down on my learning
curve, since apparently dealing with a large, well known, long
established supplier isn’t sufficient.

Sojourner


#12

I once tried to make simple bezel set studs in silver using
"calibrated cabs and stamped out bezel cups. I had to grind the edge
of the stone all the way around symmetrically to get them to fit.
Some, not all, but most.

The solution for me was to use 4 prong pre-notch cab settings, like
Tripps, they are more forgiving.Cabs can be a little too big, or a
little too small and you can still set it easily.

I used to manufacture, casting large quantities of sterling silver,
I bought heavy four prong heads, notched them to be pre-notched, and
molded them. While doing other orders for my customers, I could have
quantities cast and finished, set by my employees, and sell them is my
retail store.

When my customers want studs, 4mm, 5mm, 6mm, they do not seem to
care if it is bezel set, or prong set.

There are so many companies that make bezel set earrings
inexpensively, it is silly to compete with that market, unless you
are setting something other than garnet,lapis, black onyx, mop, ame,
malachite, moonstone.


#13

Isn’t the standard for ‘calibrated’ pushing the stone/cab through one
of those templates and making sure it fits? That in itself is a
problem, no replacement for a good pair of calipers.

Problem is, many stones are machine cut and if that machine goes
slightly out of alignment you’ll have a billion uncalibrated stones
all of a sudden.

Just curious, did you check them with a caliper or micrometer (did
you post that already?)? It’d be interesting to see how out of sorts
they are. Did they possibly ship you the wrong size?

Craig


#14

I have also experienced this problem with stones from Rio -
specifically in 4 and 5mm cabs that wouldn’t fit their sterling bezel
cups. I tried dopping the stones upside down to some nails I had in
the shop and trimmed 'em down with an abrasive wheel in my flex
shaft. Half the time they’d pop off and go flying, often into the
"black hole" under my old bench. Way too much trouble!! I agree that
things should fit in what they’re sold to fit in. No offence, Rio - I
buy a lot of stuff from you folks, but this really was frustrating.

Walk in Beauty,
Susannah Ravenswing


#15

Zen

I also use the die struck bezel cups and calibrated cabs for smaller
size stones, say up to about 6 mm. I will use them for the same
reasons as you. Quick and low cost. I generally use them on lower
end pieces where I am trying to keep the price down. Also, I just
don’t like making 3 mm bezels. Too much fiddling around to get the
bezel the right size.

Several years ago, I ordered quite a few small cabs from Rio Grande,
both round and oval. I found that they generally fit in the bezel
cups quite well. There was an occasional cab that did not fit its
matched bezel cup, but that was an exception rather than the rule. No
guarantees that the cabs you buy from them today will fit as well as
the ones that I bought a few years ago, but I would say that the odds
are pretty good that the tolerances have not changed.

Regards
Milt Fischbein
Calgary, Alberta Canada


#16

I regard myself as a hobbies although I worked at the bench for a few
years. I have taught lapidary and silver jewelry as a volunteer at
senior centers for 28 years. I make and sell a little by word of
mouth.

Regarding calibration of cabs and mountings,it takes me about two
hours to cut and polish an 18x13 cab using diamond wheels and a
little longer on silicon carbide. You can buy them for less than 3
US dollars.

It takes me a couple of hours to make a bezel or prong mounting in
silver and you can buy one for under 6 US dollars. So what if half of
the cheap ones don’t match. The only I can compete is to create
something that is so unique that you can’t buy it elsewhere,and that
is hard to do.

At Tucson I saw beautiful silver pendants with stones for about 10
dollars.

I’m glad I don’t have to fabricate jewelry as a sole means of
support


#17
There are so many companies that make bezel set earrings
inexpensively, it is silly to compete with that market, unless you
are setting something other than garnet,lapis, black onyx, mop,
ame, malachite, moonstone. 

Richard makes a great point, I try to force what I think are "my"
designs through my production system when in fact they are such
universal designs and I forget how silly I am being. When I catch
myself doing this I have to laugh and have found repeatedly that a
minor change in my design like switching from a bezel to a 4 prong
cab mount has little or no effect on my sales. While the minor
design change can increase production substantialy. The customer
won’t know the difference and probably doesn’t care either. I will
get busy to carve my own 4 prong mounts for the sizes I produce and
will fill up the shelves.

As far as one who assembles jewelry instead of “creating” I am
guilty but then really, if a customer is looking for or just happens
to see a nice pair of cabs mounted as earrings and decides to buy, I
will gladly make the sale. They are nice earrings anyway assuming
the cabs are nice. My creative genius will not be offended either by
my production or the sale of said earrings. Hell, I got over my
creative genius a while ago especially when it comes to "dot"
earrings.

Sam Patania, Tucson
www.patanias.com


#18

Hi Zen,

I had the same problem with cabs and sterling bezel cups, both
ordered from Rio. The fit of the stone varied quite a bit with the
type of stone and the country of origin: the hematites were always
too big, the carnelians and jade fit pretty well, and chrysoprase
ran the gamut from way too small to way too big and everywhere in
between.

Here’s a low-tech way to make stones that are too big (but pretty
close) fit:

  1. Flare bezel walls slightly with burnisher.
  2. Place stone in bezel.
  3. Tap stone with rawhide mallet until it is properly seated.
  4. Finish setting as usual.

Now, I’ll admit this is terribly crude and obviously won’t work with
fragile cabs, but I had no problems using this method on hematite or
harder stones. It also requires that the bezel cup can be
supported to absorb the force of the blow without damaging or
distorting the rest of the piece - i.e., for a pair of studs, just
drill a hole in a piece of wood to accept the post, while the bezel
cup rests on the surface. As for the stones that are too small for
the bezels, I’d make your own - I’ve found that it’s very hard to
make too-small stones look good and stop rattling or rotating. Not
worth the trouble.

I’m not fond, on the whole, of die-struck bezel cups - handmade are
way better for a nice piece of jewelry - but for production jewelry
that you want to keep cheap, they serve well. Provided that care
is taken to file the rough top edges and to do a good job of
finishing, they can look very nice.

Good luck, and HTH,

Jessee Smith
www.silverspotstudio.com
near Lecanto, FL for now


#19
    Regarding calibration of cabs and mountings,it takes me about
two hours to cut and polish an 18x13 cab using diamond wheels and a
little longer on silicon carbide. You can buy them for less than 3
US dollars. 

Tom, when I buy larger cabs that I intend to use in one-of-a-kind
pieces, I pay a pretty penny for them and I buy the vast majority of
such stones direct from the guy who cut and polished them. I don’t
expect such stones to be exactly a particular size, and I don’t
expect to set them into pre-made bezels. I MAKE bezels for these
types of pieces and in fact prefer free-form stones for this kind of
work.

However, I have repeatedly been asked for simple stud earrings which
are by and large not available locally (other than in cheap base
metal or WalMart all-the-same stamped out designs). I don’t want to
make such small bezels and I’m not set up for it right now anyway
(still don’t have a torch!). I’m also in a hurry right now to get
some stuff on the shelf at the artist’s co-op I was asked to join.
There’s a festival coming up in June I’d like to have SOME stuff
available for, its just so hard to get all set up and into production
after so long out of it.

Anyway, its not that I’m after cheap stones. I just wanted a quick
and easy way to satisfy a demand that goes unfilled and also get
something on the shelf as quickly as possible. I’ll try some of the
methods suggested to work around these badly calibrated and (I might
add) MACHINE cut cabs.

Sojourner


#20
    Just curious, did you check them with a caliper or micrometer
(did you post that already?)? It'd be interesting to see how out of
sorts they are. Did they possibly ship you the wrong size? 

I didn’t check them with a micrometer, they just won’t fit in the
bezel cups. They’re not the “wrong size”, they’re just not
calibrated all that well.

However, I guess I can still use them if those ear studs with the
flat pads can be glued on there. I’m looking for inexpensive and easy
here, these aren’t intended to be works of art, just nice little stud
earrings that people will be happy to bop around in.

Sojourner