There is a category of electric critters called vibrobots. I hesitate to call them robots , but I guess they are autonomous moving things. Anyhow, as usual, I have bits of junk laying around that tend to rear up and get in the way now and then. I have an old motor I salvaged out of a vcr or something. I also had wire insulation hangers from my crawlspace insulation project. That’s about all you need to build a junk vibrobot. I bent a paperclip in an L-shape and taped a screw to one end of it. The screw attached off center of the motor shaft throws the balance of the motor off so it vibrates. Since it is attached to rigid, skinny wire feet, the vibrations through those feet on a hard surface translate into motion…random motion! So, I zip-tied the end of the paperclip without the screw to the shaft of the motor. I then bent the insulation hangers in an arc and zip-tied the 2 sets of legs around the motor. I hooked a 9-volt battery to the motor contacts and away it went. I tried putting little rubber feet on it but the bare wire on hardwood jittered the best.
Mo, our silly cat had to get in on the fun. The kids had a blast running the v-bot around Mo. They had it timed perfectly so he would jump in the air when it started spinning. For a cheap toy, it was quite a bit of fun! Just a word of warning though…if you do this on your dining room table, be sure the cat is not around. Also, be sure your wife is not around as she will not be impressed with the cat on the table or with the little scratches the v-bot feet leave. Of course, this is certainly not the first time I have scratched the dining room table…but that’s another story.
Here are some other vibrobots that other people have made. I have seen some that are solar powered, some that look just like bugs, and some that are made or worse junk than mine.