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Our first design was for an aquamarine pendant set in 14-karat
gold with five bead-set diamonds. Nancy cut a five-sided stone,
an original shield-cut design, to best use a large piece of aquamarine
rough. The cut aquamarine showed great color and sparkle, but its
odd shape did not generate much interest with customers, and we
agreed that if we didn't set the stone, it probably wouldn't sell.
We have found that odd-shaped stones produce unique designs that
sell only when they are already set in jewelry mountings.
We settled on a design that best complemented the chevron-shaped
stone, and rendered a jewelry image that closely followed its geometric
lines. We decided to set five small diamonds in a straight line
along the top using small beads manufactured in place. With the
small beads and predrilled, tapered holes precisely placed, it was
a simple task to set the diamonds. The design had a basket underneath
the stone that was invisible when viewed from the top. Precise dimensions
of the stone's width and pavilion angles were used to establish
the dimensions of the seat in the gold pendant mounting. We established
these dimensions to have the stone dropped easily into place and
secured with two tabs along the top. These tabs were pushed over
to provide a very secure setting without covering up much of the
stone. The design software allowed us to incorporate a loop for
hanging a lovely creamy pink freshwater pearl below the aquamarine.
The design began with a scan of the stone. By laying the stone
on the scanner, we could create an image that could then be traced
in SolidWorks. We now have the ability to export the stone's geometry
directly from GemCad (www.gemcad.net)
using a VRML file format. This allows us to see how the stone and
the design will interact. In SolidWorks, each component of the design
is built from two-dimensional sketches located on three-dimensional
drawing planes. These sketches are then transformed into three dimensions
by using sweeps, lofts, and extrusions. The bead settings for the
diamonds were exactly placed along the top plate, and the finished
part reproduced this level of detail in gold with extraordinary
accuracy. Setting the diamonds became a very easy task. We did have
to use a hart bur to fine-tune an exact fit for the diamonds, but
the setting time was greatly reduced. |
Return to
the Main Story, "CAD/CAM for the Studio Artist"
TOP: The computer-designed and manufactured setting
for the pendant shown BELOW. The seats will correspond precisely
to the gemstone the artist wishes to set.
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