replace the old batteries with new ones. Make sure you are using small tires. And, Make sure there is no contact between the rotating shaft and other lego parts

Every time we have to replace batteries we lose the firmware and have to re-do our programs.

RCX-based LEGO Clock

In this underwater activity students make an automated buoy.

Think about when you give students accessories and LEGO People. Kids can often get distracted with decorating over the goal of the activity. I give students people once they have passed whatever tests their creation needs to pass.

Lego RCX Piano - made with 3 touch sensors

I find it helps to keep young children (early elementary) more focused on the task at hand if they only have access to the pieces they need. For example, I usually take the motors and battery packs out of the Simple Machine kits.

Do Inventor files exist for Lego components? I'm wanting to use them with the NXT platform

We are running NXT-G, version 1.1 with firmware 1.05. Someone in our workshop wrote a 1-block program to make motor b,c go forward for 5 rotations. When the program runs, one motor stops spinning immediately - while the other continues to the full 5 rotations. We've switched the motors, the wires, t...

James Watt used the so-called "flyball governor" to regulate the speed of his steam engines (1787). It consists of two flyballs which are connected to the spindle by two flyball arms. The spindle of the governor is directly connected to the shaft of the steam engine. The flyballs move upward when th...