This summer I taught 2 kid camps using Pitsco's new Tetrix Prime robotic set and I'll have to say that I absolutely love how easy this set is to use. The robots are constructed from 16mm aluminum beams and plastic connectors. Pitsco's new quick rivets and thumbscrews make prototyping simple and quick. The kids literally had time to make 6 different robots during our week-long camp. You can find building instructions for several different designs here.
The kits require a little pre-assembly by the teacher to put together the gripper arm and to pair the receiver with the controller, but it's worth it. The gripper is so much sleeker than the clunky design described in the Tetrix Max builders' guide. The robots are remote-controlled with a double joystick controller (included with the kit) so you can configure the robots for arcade or tank-style driving. Pitsco sells a module that will allow autonomous control of the robot's motors using LEGO's EV3 or NXT, but this is an additional $54. Instead we added an NXT and a light sensor to each robot to give audio feedback (a beep or sound file) whenever the robots drove over little squares of blue tape. I think the kids had a lot more fun driving the robots around to find the tape than they would have had watching the robots find the tape autonomously.
After that activity, I started wondering if I could use that same technique to add a Vernier sensor to my robot. Sure enough, I built a little holder for Vernier's Magnetic Field Sensor, programmed the NXT to beep whenever it detected a magnet, and then scattered little neodymium disc magnets all over the floor. This would be even more fun for kids if the magnets were hidden underneath plastic cups or little Lego bricks.
