If you have worked on robots or other wheeled projects, you may have heard of Mecanum wheels. These seemingly magical wheels have the ability to move in any direction. If you’ve seen one, it’s obvious how it works. They look more or less like ordinary wheels, but they also have rollers that rotate 45 degrees away from the normal axis of motion. This causes the driving force of the wheels to move at an angle of 45 degrees. However, many details are not obvious from a quick glance. Why are rollers tapered? How do you use these wheels to control the vehicle? [lesics] in a recent video, you can see how the wheel works.
For four wheels, you can have a pair of wheels – one at the front right and one at the rear left – with a net force vector of + 45 degrees. Then, another pair of wheels can be manufactured in different ways so that the net force vector is – 45 degrees. The video shows how moving some or all of the wheels in different directions can move the vehicle in multiple different directions.
It is easy to confuse Mecanum wheels with omniwheels, but they are different. Although both have a master wheel with rollers, omniwheel’s rollers are at a 90 degree angle to the spindle, so they can slide in this direction. These are commonly used in triangular configurations called Kiwi drives. Mecanum wheels are not without disadvantages, including cost. But you can do it yourself.