Models View all Animated Double Rack and Pinion gear 8 437 0 Animated. Spur Gears 6 66 0 Animated. Spur Gears and Idler Gear System. 6 166 0 Animated. Internal Spur Gear Transmission. 6 282 0 Animated. Round Rack and Pinion Gear. 10 433 1 Animated. Rectangular Rack and Pinion Gear. 14 1053 1