I’ve made another round of digital-to-silver jewellery: a pair of Super Mario Bros. cufflinks and a pendant for my crowbar-loving wife. For my last jewellery project I had Shapeways manufacture cufflinks directly in sterling silver, but for these pieces I did it a little differently: I had them 3D printed in plastic, used the plastic prints to make molds, had them cast in silver, and hand-finished them. I couldn’t have done the casting and finishing without the help of my friend Norah Kerr, who held my hand through the entire process.
Keep reading for the full breakdown of how I did it, more pictures, and source files for the 3D models.
This was the easy part: I made the 3D models (OpenSCAD for the cufflinks, Blender for the crowbar), uploaded them to Shapeways, and had them printed in their Frosted Ultra Detail material. If you’re interested in printing your own or modifying the files, here are the cufflinks (Shapeways, Thingiverse) and the crowbar (Shapeways, Thingiverse).
In addition to being a skilled jewellery-maker, my friend Norah professionally solders circuit boards for satellites. She is a total maker hero, and patiently indulges my requests for metallurgy and soldering help and advice. Norah pointed me in the direction of HL Casting, one of several professional casting businesses here in Toronto. The people at HL were a pleasure to work with. For about $20 each they made rubber molds of my originals. These molds are then injected with wax, which is then used to perform lost-wax casting to make the silver copies.
The real work begins after the silver has been cast. At the point the pieces are whitish, have a piece sticking out from where the silver was poured (called a “sprue”), and show marks from the seam in the mold.
Norah and I removed the sprues using a jeweller’s saw (which cuts through silver like a knife through hot butter) and filed down the marks from the mold, and polished them with a combination of tumbling in a polishing agent and detailing by hand. All told, it was several hours with of labour (including Norah teaching me what to do) spread out over three or four afternoons.
Why not just print in silver?
For the most part I’ve been happy with Shapeways’ sterling silver prints. The main place it falls short for me is pricing ($30 flat + $20/cm^3). If you’re making very small pieces, or multiple copies of the same piece, it’s much more economical to use a reusable mold. There are also other benefits to doing one’s own casting: it sidesteps Shapeways’ design restrictions for silver. That means much higher detail, more control, and multi-piece items become financially feasible. A mold can also be used for other materials, like gold, if you’re so inclined.
The downside, of course, is that it takes a lot more time and effort.
Would I do it again? Probably. I’d say the choice between casting it myself and having Shapeways do it really depends on the piece itself and my mood. Both ways have their merits, and I’m happy to have both options available to me.