Bronze

Sheet aluminum, rods, and wire

Steel wire, wood base, and electric motor

Shallow wooden box, metal attachments, wooden pulleys, round rubber belt, and electric motor

Steel tube frame, steel wire, painted cardboard, and electric motor

Shallow wood box, wood pulleys, round rubber belt, wire and paper attachments, and electric motor

Wood panel, polychrome wood, metal, wooden pulleys, round rubber belt, and electric motor

Round rubber belt, steel rods, painted sheet metal, wire wooden pulleys, two clothes pins, and electric motor

Bronze

Bronze

Steel rods and wire, aluminum pulley, brass bell, round rubber belt, and electric motor

Iron

Polyester and cloth

Sheet steel base, steel rods, fur pelts, horse hair, and electric motor

Welded steel, epoxy, canvas, fabric, saw blade, and wire

Structural steel-channel base, steel rod, small tricycle wheel without tire, round rubber belt, and electric motor

Steel plate, iron and steel spoked wheels, slant line pulleys, rubber V-belt, and electric motor

Steel, steel pipe section, iron wheels, rubber V-belt, flat belt, and electric motor

Bronze on marble base

Canvas, wood, and polyurethane foam

Painted steel

Steel

Pressed ceiling tin, nails, and wood