With tutorials, courses and building instructions with gears you could learn how to use Gear Wheels, Warm Gears and Racks. Everything spins. With a few gear wheels you could make it spin faster or harder. Check out the examples of different constructions, robots and attachments that make use of gear wheels.
Part four of the Catapult series is again about loading the catapult automatically but this time using EV3 brick, motor and sensor. We use a gear system with a medium complexity along with a "standard clutch" available in the LEGO Mindstorms EV3 kits. As a result, at the end of the video, the Catapult loads and fires automatically.
In this second video lesson on catapults we improve the stability of the base of the robot. An important feature of the new base is that it is not bending. Use the same principle in all of your constructions to achieve better, stronger robots.
In this video we are solving part of the FIRST LEGO League Senior Solutions challange missions (FLL 2012) using LEGO Mindstorms NXT robots. I make a step by step explanation of each move I make. The goal of this video is to help you with ideas and suggestions on how one should look at the missions.