Separate the robot construction on body - body and attachments. Attachments should be small, light and most importantly for winning the competitions they should be pinless. In this category we group tutorials, courses and materials for different attachments that have proved to be useful.
This flip attachment from LEGO MINDSTORMS Robot Inventor 51515 set is design to flip parts. It can flip a manhole for example, but could also flip other parts. The principle of flipping is quite interesting as it uses two axles and a border.
The purpose of this attachment is to flip the tires in the FIRST LEGO League 2020 Replay competition. There are two tires on the field. The attachment must flip them and return them to their initial position. This is an extremely interesting attachment that is using friction and force in order to flip the tires.