Caster
Videos
A caster is an undriven wheel that is designed to be attached to the bottom of a larger object to enable that object to be moved.
A swivel caster
Two wheeled swivel casters on a desk chair (no fork)
Four heavy duty casters on a large subwoofer whose weight can exceed 500 pounds (230 kg) depending on driver and top loading, and must be able to withstand rough handling.
A swivel caster with a wheel lock. The vertical swivel on this type of caster cannot be locked in position.
Omni wheel
Videos
Omni wheels or poly wheels, similar to Mecanum wheels, are wheels with small discs around the circumference which are perpendicular to the turning direction. The effect is that the wheel can be driven
Caster
…A standard wheel has a center rotating hub (or bearing) and a compliant material on its outer side. An omnidirectional wheel (Mecanum wheel, Omni wheel, or Swedish wheel) is made of a large central hub with many additional smaller wheels mounted along the perimeter such that their axes are perpendicular…
Triple Rotacaster commercial industrial omni wheel
A molded plastic omni wheel
Robot soccer
Robotino, used for educational, training and research purposes.