Introduction: How to Make a Simple Spiderbot for Halloween

By

This is a simple, fun bristlebot for Halloween! Bristlebots are great starter projects for folks learning the basics of circuits and robot construction. Using the head of a toothbrush for the body, a small motor to provide the motion, and a battery to power everything, bristlebots are easy to construct, inexpensive and lots of fun. As such, they're great for an introductory project in the classroom or makerspace.

Supplies

We'll need some basic supplies to create our spiderbot. I use small vibrating motor purchased through a retailer, but for an added challenge you can hack an electric toothbrush or an old pager for the parts instead.

  • Hot glue gun and glue sticks
  • Scissors
  • Wire Strippers/Cutters Diagonal Cutters
  • Vibrating Mini Motor Disc 10mm diameter (I suggest Digikey Part # 1597-1245-ND.)
  • 3V coin cell battery, CR2032 or CR2025 (You can purchase them on Amazon.)
  • Electrical Tape
  • 1-inch black pom-pom
  • 1 black pipe cleaner
  • 2 small paper clips
  • Double-sided adhesive foam squares
  • Toothbrush
  • Google eyes

Step 1: Step 1: Assemble the Spider Body

We'll start by building the spider body. Using your scissors or wire cutters, cut the pipe cleaner into four equal pieces. Twist all four pieces together in the middle, spreading the legs out into a star pattern. If desired, bend the end to make "feet.". Glue the eyes onto the pom-pom. Glue the pom-pom onto the center of the legs.

Step 2: Step 2: Build the Battery Pack

Next, we'll build the battery pack. Cut a piece of electrical tape about 2 inches long. Starting at one end, place a paperclip. Stack the battery on top of that paperclip. Place another paperclip onto the top of the battery. Wrap the remaining electrical tape around the battery to secure the clips to each side.

Step 3: Step 3: Assemble the Spiderbot

Using your cutters, separate the head of the toothbrush from the handle. If the head has a rubberized surface, you may need to remove it to get good adhesion with the battery and motor. You should choose a toothbrush that has fairly flat bristles, as they make it easier to balance the bot. If your bristles aren't flat, consider using scissors to trim them.

Before hot gluing all of your pieces in place, test with double-sided adhesive foam pieces. It can be challenging to get the balance just right for the best movement, and using foam make is possible to remove pieces more easily. Once you have everything that way you like it, remove the foam pieces, one by one, and hot glue items into place.

Build your stack as such, bottom to top: toothbrush, battery pack, motor (centered), pom-pom spider. Make sure the wires from the motor extend out over the paperclips. The paperclips can face the front or back, as you prefer.

Once your bot is built, it's time to power it up. Simply attach the exposed wire from the red lead to one paper clip and the exposed wire from the blue lead to the other paper clip. The order doesn't matter, though technically the red lead should attach to the positive (smooth) side of the battery. The bot will vibrate either way it's connected.

It can be helpful to wrap the long wires around the body of the spider to keep them out of the way. Use wire strippers to expose additional wire if needed to ensure a good connection. Be careful not to have any of the spider legs touch the paperclips, as the wire in them will conduct electricity and can short the circuit.

Step 4: Step 4: Play With Your Spiderbot

Once all the spiderbots are working, test to see how bending the legs can change its movement, or create battle rings out of pipe cleaners and see which spiderbot stays in the longest. Decorate your spider with additional eyes, feathers or glitter paint, as desired

Happy Halloween!

If you enjoyed this project, please visit my website for more fun or check out my book, "The Big Book of Maker Camp Projects."