A wind-up desk companion. Wind the rear knob a few turns, set Trotter on a desk or tabletop, and watch it trot forward on four legs with a smooth, lifelike gait. No batteries or motors - just a wound rubber band driving two crankshafts. A tactile fidget or display piece for a desk, shelf, or gift for makers and kids.

How it walks. Twist the knurled knob at the rear to wind an internal rubber band housed in the chassis tub. As it unwinds, it turns the crown gear and two crankshafts, whose coupling rods swing the front and rear legs in turn through the hip discs, giving Trotter a steady four-legged gait with no batteries or motors.

Precision printed parts. Each leg is built from precision-printed pivot joints - hip discs, guide pins, and lattice-braced web brackets - that let the upper and lower leg sections swing freely on four axle stubs. Fine layer lines run across every panel and foot pad, and the chassis tub and lid snap together to house the winding mechanism.