Gears and gear racks use rotation to transmit torque, alter speeds, and change directions. Gears can be found in many different forms. Spur gears are fundamental, straight-toothed gears that run parallel to the axis of rotation. Helical gears possess angled teeth that steadily engage matching tooth for smooth, quiet operation. Bevel and miter gears are conical gears that operate at a right position and transfer motion between perpendicular shafts. Change gears maintain a specific input speed and enable different result speeds. Gears tend to be paired with gear racks, which are linear, toothed bars used in rack and pinion systems. The gear rotates to drive the rack’s linear movement. Gear racks provide more feedback than additional steering mechanisms.