Caster Wheel

Caster Wheel is an omni-directional wheel. This wheel can be used as neutral wheel for the robot.

A caster wheel (or castor) is an undriven, single, double, or compound wheel that is designed to be mounted to the bottom of a larger object (the "vehicle") so as to enable that object to be easily moved. They are available in various sizes, and are commonly made of rubber, plastic, nylon, aluminum, or stainless steel. The outer diameter of a caster wheel affects how easy it is for the caster to be able to move across rough or irregular surfaces. Large diameter caster wheels are able to bridge wide gaps where a small caster would fall inside and get stuck, such as the gap in the floor between an elevator door and the elevator car. However, the larger diameter a caster wheel, the higher or wider the caster support arm must be. Either the base of a low-hanging object must be lifted higher above the wheels, or the casters must hang out to the sides straddling the low-hanging supported object. Large diameter swivel casters also typically need much more room to rotate the vertical shaft than a small caster.

Ball transfers can be used for conveyor or caster applications.  In the traditional "Ball Up" configuration, ball transfers make an excellent conveying surface.  Ball transfers allow for omnidirectional movement across the conveying surface.  They are perfect for applications where manual lateral and rotation movement are required.  In the "Ball Down" position, ball transfers are a unique caster: a swivel caster without the swivel section.  Swivel casters have to orient themselves into position, so off the line you have to put energy into getting the casters in alignment. With a ball transfer caster, the caster is always aligned, as it has omnidirectional rolling. Metal ball transfers are acceptable for use on hard floor surfaces and short pile carpet.  Note that metal ball transfers should not be used on hardwood floors.