Okay, so technically this is not a robot. It doesn’t have any sensors. It doesn’t have a controller or computer chip. It isn’t responding directly to external stimuli. But, hey, you have to start somewhere and my kindergartener definitely thought our homemade wigglebot was cool. He was so excited by our wiggly, spinning, little motorized guy that he’s already making big plans for our next “robot”, which he says will have arms. (I had to explain to him that, unfortunately, I did NOT know how to make microbots like in Big Hero 6, but he was impressed enough by my skills that he didn’t immediately assume they were off the table.)
The idea for this bot came from the book Robotics: Discover the Science and Technology of the Future. The specific project that motivated this activity was the Art-Making Vibrobot on pages 24 to 26, though I modified the supplies considerably and the technique slightly. Basically this little “robot” is just a cup with marker legs that vibrates and spins due to the motor being off balance. As it jiggles around on a piece of paper it makes interesting designs. While I hope to make more exciting and complicated projects with my kids as they get older, this was a nice unthreatening activity to start with which showed my child how to hook up a simple DC motor to a battery. He’s already familiar with some of these electrical concepts through our Snap Circuits set (link to my review), but this was a fun, hands-on supplement to the more structured activities in that set.
Check out this video if you would like to see a demonstration of how one of our wigglebots moved, though they each have their own unique personality depending on the length and position of the legs.
Recommended Age Range: Kindergarten, Elementary
Time Required: ~30 minutes
Cost: Less than $8 in used supplies (The motor was $3.50 and the battery holder was $1.50 at Radio Shack (our local electronics store). Everything else we already had on hand.)
- Disposable cup
- Electrical tape
- 3 Markers
- 2 “AAA” battery holder (affiliate link)
- 2 “AAA” batteries
- 1.5-3 V DC Motor (affiliate link)
- Popsicle stick
- Googly eyes (optional, you could always just draw them on)
Supplies & Tools:
- Permanent marker (to draw face, not shown)
- Glue (optional, for attaching googly eyes. Note that the picture shows Elmer’s Glue, but we ended up finding the hot glue gun worked better.)
- First tape the markers into the cup as legs.
- Next attach the battery pack to the DC motor by wrapping the wire around the leads on the motor. (When my kids are older, i’ll teach them how to solder, but for now, this is sufficient.)
- Now that the battery pack is attached to the motor, tape the battery pack onto the top of the disposable cup slightly off center. I cut the strips of electrical tape in half.
- Next tape the DC motor onto the cup.
- At this point you could turn on the motor by placing the batteries into the holder, to see that with the motor not off balance, nothing exciting happens. Next add on the clothespin to the motor and it should start to wiggle a little bit.
- To make the wigglebot wiggle more, you need the motor to be more off balance. I accomplished this by taping a popsicle stick to the clothespin. However, then my clothespin would frequently fall off of the motor due to the strong vibrations, so I folded the end of a long narrow piece of electrical tape over the motor and then wrapped the tape around the motor so that the sticky side was facing out.
- Attach the clothespin and weight to the motor.
- Make a face on your wigglebot, plug in the batteries, place it on a piece of paper and watch it wiggle and spin!
Note that unlike a prepackaged robotics kit which provides very specific instructions, this can be viewed as an open-ended activity. While the “tape fix” to get the clothespin to stick to the motor worked, one could definitely try to think of improvements to be able to cantilever more weight off the axle in order to make the wigglebot vibrate even more. The robotics book mentioned above recommends sticking a piece of cork into the shaft. There are also other adjustments that could be made and you should definitely encourage your child to ask questions and try to find solutions. What would happen if the legs were not all the same length? What if we attached the motor at an angle or sideways? What if we taped on more legs? I don’t know. What if?
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