Saturday, October 20, 2012

Working with CAD

Have you ever wondered how it is that some Etsy shops carry designs that look commercial but claim to be made or designed by the shop?  They probably use a 3D jewelry design software like Rhino.  I always wanted to try something like this, but I figured it would just take too much time to learn.  But then last summer, I met Brandy of Belenky Girl Designs, a freelance jewelry designer, and we’ve started working together.  My first earrings are already out; an eternity band and a halo ring are in production and should be ready for the holidays.

Kyanite Earrings with Settings by Brandy
So how does CAD design work?  CAD stands for “computer aided drafting” and there are dozens of software packages out there, ranging from industrial uses (i.e. for making auto parts) to the more fun, like jewelry design.  When the design is done, the computer model is “printed” in 3D, that means a plastic or wax model is created directly from the file by a 3-D printer, which adds layer upon layer of wax or plastic until the model is fully “grown” (yep, that’s the lingo).  The model then cast in your favorite metal.

CAD design is not cheap.  The standard price for a model is between $100 and $200, depending on how elaborate your design is.  Plus growing costs, which can be up to $50.  Remember also that you need to discuss a lot of details with your CAD designer.  You have to provide exact measurements of your gem, have an idea of the dimensions of the piece, i.e. how wide and deep a ring should be, domed, flat, tapered, prong style, etc.  All this is part of the design time you pay for, and the actual design can still take an hour or two.  Then you add in the casting, and of course the metal cost.  So a CAD design is worth doing only if you want to have something done in gold for an expensive stone, or if you plan on making more than one piece, like me.  I can work the cost of the original into the jewelry price, if I sell enough pieces.

What are the advantages of 3D design?  You can get symmetry and precision that is nearly impossible to achieve in metal or wax.  Think of the dozens of tiny prongs on a halo ring, or the perfect curvature of a custom design tapered ring.  Making a wax or metal model takes hours and is very easy to mess up.  I’m not a jeweler by training, so I can do neither (the organic look of my own wax rings, by contrast, is easy to get).  Meanwhile, the wire you can buy for the rings I solder is either flat or domed, and that seriously limits the design.  Just being able to solder together the settings for a 3-stone ring requires weeks of practice – sort of like playing even a simple Schubert piece on the piano (forget Chopin!).  If you make many castings, you also save money over buying the parts each time, or having to buy finished models elsewhere at a markup.  Plus of course CAD opens up a wealth of options beyond the traditionally available parts (even though there are a lot).

My Eternity Band (top) with Round Bezel Settings, and an Open Version for a Stone
I personally decided on CAD designs because a lot of my stones are very deep.  Many colored stones are have a bulky back which preserve the color.  They’re not flat like diamond cut stones, so many of the traditional settings prove too shallow or the prongs too short to grab the stone.  Some of the silver settings, in turn, are too flimsy and the prongs can break off during setting. 

There are also some disadvantages to CAD designs.  The main one, right now, is a limitation of the printing and casting process.  You cannot get as much detail with a casting as you can when you work directly in the metal.  Consider the little filigree pendants I’ve been selling lately.  Those were made in the 1920s, some are stampings (where the metal is stamped out directly and the design imprints itself onto the metal), others have tiny millgrain that is applied with a special tool.  For a wax model to capture a design, it has to be about 1/3mm deep, which means that some engravings and textures don’t show.

I figure, however, that in time, both the growing and the casting process can be done with more precision, plus the design software will be easier to use.  This will also lower the cost of production.  Then maybe anyone can make jewelry at home.  (Is that a good thing?)


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