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