This is the first biped walker that I built with the NXT. It’s bigger than Alpha Rex, and it walks a bit less elegant. Yet, it actually lifts its feet off the ground to walk. It walks by lifting up one foot, while turning the foot that is currently on the ground. When it does...

This little dog was developed in November 2007. It walks around while wagging its tail and while looking for humans or objects in its way. You can build it if you have the NXT 1.0 set and three extra gears (details below). Building instructions and the program are available for download. This is a picture...

This is the fourth evolution of brick sorters! This time sorting 10 types of bricks: 5 colors and two sizes. You can simply throw a set of bricks into the sorter, and the machine will handle the rest. Compared to sorter #2, this one is more reliable and more functional too. This robot uses both...

This robotic arm combines the power of the RCX and the NXT. The robot turns on its stationary base while grabbing objects around it. The RCX and NXT talk to each other by sending light pulses with light sensors. The RCX acts as the on board master, and it receives infrared control messages from a...

This line follower uses three light sensors. One of them is an NXT light sensor, while the other two are RCX light sensors, attached to the NXT with custom converter cables. To make a converter cable, cut one NXT cable and one 9V style cable. Next, connect the black and white wire from the NXT...

This is an update of the RCX rack-and-pinion steering car. The back wheels are driven by one motor. A motor in the front allows for steering using a rack-and-pinion steering mechanism. An ultrasonic sensor in the front detects whether the car is near a wall. If so, the car will back up and start driving...

Admittedly, the ever popular RCX chimney climber was extremely slow. To compensate, here’s a quick version that will travel the same distance in only a few seconds. Still, this robot is equally unstable as its predecessor, because of its badly placed center of gravity.

February 2007 brings you the NXTified version of the disc shooter from the RCX Ultimate Builders Set (#3800). This shooter fires discs when the robot detects any objects with its Ultrasonic Sensor or when it hears a loud sound with the Sound Sensor.  The shooter wheels rotate at a different speed (see the gearing), so...

This robot arm closely resembles the arm that appears in the RIS 2.0 (RCX) set (#3804). But since the NXT set has three motors instead of only two, this design uses independent motors for grabbing and lifting. A third motor is used to rotate on its base. An ultrasonic sensor is mounted on the robot...

This is a direct copy of the walker built with the RCX, primarily built to try out the new NXT system. This build was in fact slight more difficult than the RCX design, because of the NXT motor shape. The only easy way to create two motorized shafts was to use a chain, as shown.