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.

The RCX robotics set has many so-called studded pieces: bricks with the well known LEGO studs on top. The NXT uses primarily studless pieces: beams and connectors without studs. Both type of pieces have their advantages, but building with these different pieces requires different building skills. Before migrating to the NXT system, I decided to...

Second in the series of brick sorters is this machine, which sorts black, grey and white bricks and seperates big from small bricks. Bricks are thrown into the brick store, go down to the conveyor belt one by one, and are put into one out of six bins on a rotating platform. Each time I...