Build a Shadow Avoiding Robot

You can build a simple robot that responds to a stimulus (the lack of light) by stopping one wheel and reversing the other. This simple maneuver may help the robot leave the shadow it entered and find the light. Once it does, it will drive forward again. Sometimes, the poor little robot will get caught in the shadows and will spin in circles until you rescue it.

This robot is an excellent project for beginner robot builders of any age. I used this design successfully to teach a class full of kids aged 6 to 12. If an instructor or other adult pre-solders the wires to the two motors, it can be built by the student entirely without soldering.


By making this simple robot, children and students of all ages will learn several basic concepts used in robotics. These concepts include differential steering and motor control, sensors, and automated behaviors. In addition, students will gain experience with hands on construction and prototyping a circuit on a solderless breadboard.

You can find complete instructions, materials and parts on Instructables.com at:
http://www.instructables.com/id/Introduction-SpurtBot-ShadowRunner/

Solder Fume Extractor From Old Hair Dryer

I have made a couple of solder fume extractors using Altoids tins. You can find instructions for these on the Internet. However, I always found that I had to get the extractor very close to the soldering, and this was not always easy to do.

The other day I was clearing out my workbench, and I found an old hair dryer saved from another project. It struck me that with this, I could make something that was much easier to position close to the source of the solder fumes.

It turned out to be very simple. I think the video explains it well. Here are the parts, materials and tools I used.

• One old hair dryer with most of the guts ripped out
• One 7.2V 3800mAh NiMH rechargeable battery pack (from Tenergy)
• One CTMF 7.2V Connector Set for Tamiya (from Muchmore Racing)
• A piece of Cut-to-fit carbon filter
• Some 18 gauge black/red wire pair
• Electrical tape
• soldering iron and solder
• screw driver
• Pliers

Easy.