Normal vehicles go forwards and backwards, but need to turn in order to go left or right. If, however, your rover or robot uses specialized Mecanum wheels, it can actually slide in any direction you desire. The trick here is that, in addition to the cylinder that rotates with its driving motor, each wheel also contains a series of sub-rollers positioned at 45° to the main axis of rotation.
For this project, Dejan of “How To Mechatronics” has used Mecanum wheels to create a unique remote-controlled robot. As they can be quite expensive, instead of buying a set, he actually designed and printed the wheels himself, with sub-rollers that rotate on lengths of 3mm wire. Each wheel fits up to a NEMA17 stepper motor attached to his custom chassis, providing precise and repeatable movement.
The robot is controlled via an Arduino Mega, along with a custom shield that houses DRV8825 stepper drivers and both an nRF24L01+ radio and HC-05 Bluetooth module. This dual-wireless setup enables the robot to be driven by either a custom RF remote or a smartphone depending on the code loaded into it. Its custom app not only allows for direct driving, but takes advantage of the stepper motors’ repeatability to record and play back movement sequences.