In line with my desire for a 3D printer like the CupCake that uses conductive build material, here is a printable RC filter. The two spirals are a resistor and a capacitor. As you might have noticed, one of the spirals is continuous (the resistor) and the other has a gap in the center (the capacitor). Use of the circuit is just a matter of attaching power or a signal across the two thicker terminals perpendicular to the line formed by the spirals. This kind of circuit could probably be printed with traces on a PCB. Made in Inkscape and Blender.http://makezine.com/go/makerbotThis is a 2D design extruded so it has volume. The block underneath is just to support the thinner sections. Ideally, the block would be dielectric/plastic while the design on top would be conductive.