Apparently I’m not the only one charmed by the simple elegance of the Geneva wheel movement (Wikipedia). Thingiverse users PrintTo3D and raumfahrtagentur have created printable and laser-cut-able versions, respectively, of the classic mechanism, which converts continuous rotary into intermittent rotary motion, with positive locking of the stationary shaft between cycles. PrintTo3D has also posted a YouTube video showing the final printing, assembly, and action of his model.