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.
Active robot attachment for the LEGO Mindstorms EV3 Box robot chassis. The attachment is placed on the top of the robot and uses a system of two gear wheels to transfer the motion to a lever and to .... lift things.
This robot attachment shows you how to limit the rotation of a lever. It uses two gear wheels to transfer the motion on 90 degrees.
It could be built with LEGO Mindstorms EV3 and NXT versions. Most of the time during competitions like FIRST LEGO League and World Robotics Olympiad you need a lever for just a limited motion