Collection of Seal Rings
Machining jewelry wax models on a Roland JWX-30Goldsmith Gijs Borms sells both his own designs and jewelry of other brands. All products are on display in his shop DeDock goud en zilver in Utrecht (the Netherlands). His jewelry workshop is located on the same address.
One of the rings in CAD (Rhino screenshot) without the stone.
One of the specialities that Gijs offers is a series of seal rings: massive rings in silver or gold, with a stone selected by the client. Four models are available: oval stone, oval with bands, faceted and the
"TV-model". Each model is available in a range of sizes, resulting in a complete collection of seal rings.
These rings all have been created using CAD/CAM technology. The designs have been modelled in Rhino, and DeskProto has been used to create the wax models for casting.
Same ring in DeskProto. First the rotary paths, next plain XYZ toolpaths to machine the stone's seat.
Reasons to select CNC machining for the wax models were that the wax-surface of a milled model is much smoother than of a printed model, and that for these massive rings milling is much cheaper than 3D printing (where the print volume sets the price).
Reasons to select DeskProto for the toolpaths were that DeskProto does the job quickly (both calculating the toolpaths and machining the model), and that DeskProto is very flexible: the ring's main body is done using a ballnose cutter, while the stone's seat has been machined using a flat cutter. These last toolpaths were plain XYZ toolpaths, even with the wax-model on the rotary fixture.
Machining side 1, and next the 'autoflip': a 180 degree rotation.
The illustrations on this page show machining a wax-model on the Roland JWX-30 machine (no longer in production). This machine came with four different clamps, suited for various types of jewelry. Here the small square clamp is used (see the illustrations), which allows machining from two sides with an "autoflip", and rotary machining.
A nice detail of the JWX-30 is that it features a completely automatic referencing process that accurately sets the workpiece zero point for each fixture.
Sides 1 and 2 are ready. Followed by mounting the wax for the rotary pass.
In DeskProto a special wizard for the JWX-30 is available (also see the JWX30 video), which makes it very easy to create the toolpaths for a ring model in this clamp. The wizard automatically creates three parts in DeskProto (side 1, side 2 and the rotary part), and a number of operations for each part. Including some 2D operations to create a core support hub that fits the rotary fixture of this clamp.
The wax model for the seal ring as shown in the illustrations was machined using this new wizard: far more quickly than when using the CAM software that came with this machine. Only one cutter was used: the 1 mm diameter ballnose cutter that came with the machine.
Rotary machining left, and detailing the seat right.
The rotary toolpaths smoothen the outer ring where the toolpaths for the two sides meet, remove the outside wax supports (spokes) and remove wax where the cutter could not reach from the sides (for this ring inside the seat, where the stone will be placed).
Still for this ring the complete stone seat cannot be done with only rotary toolpaths. So a fourth part has been added, using XYZ toolpaths, to completely machine the stone's seat (illustration above right).
Left a few wax models, right a few rings just cast in silver.
A complete series of wax models have been made: for all four seal ring models in various sizes. Each wax model then was used to create a wax mould: in the production process of a ring the wax model will be lost, and for each of these rings the intention is to create more then one.
The resulting cast waxes then could be used to cast the actual rings in silver or gold. The illustration above shows the castings before finishing. On the ring in front you still can clearly see the rest of the sprue (channel for casting the molten metal).
Three rings, and next two rings with a cameo in the stone.
Each ring can be customized by engraving the stone's surface. A simple text can be engraved, a more complex graphics like a family crest, or even a complete relief like the two cameo rings shown above.
This allows creating a unique ring using a 'standard' ring geometry.
The collection of seal rings on display. A display like this includes sufficient rings to show a client what his/her ring will look like.
The display above shows all four types of seal ring, with for each type a number of sizes and different stones. DeDock welcomes requests of Dutch jewelers who are interested to become a reseller of this ring line.