At Home With Hands On!

Electric Motor Madness (12/6/17)

Build a Scribble-Bot:

MATERIALS:

  • AA Battery
  • Double-ended Alligator Clip Leads
  • Wire cutter/stripper
  • Mini DC Hobby Motor (1.5 Volts)
  • Electrical Tape (insulating tape)
  • Duct Tape
  • Small container (such as a plastic cup, short Pringles tube, or even a tin can)
  • Hot Glue Gun
  • Glue Sticks
  • Washable Markers
  • White Paper
  • Craft supplies (especially Googly Eyes!!)
  • Adult Assistant

INSTRUCTIONS:

 

  1. With help from your adult assistant, cut in half the wire of a double-ended Alligator Clip Lead. Strip away about ½ inch of the plastic coating from each of the cut ends.
  2. Using the electrical tape, attach the exposed copper wire directly to each of the Positive and Negative terminals of the AA battery. Use plenty of electrical tape here, because the tape will help to insulate the wires from possibly shocking anything, and it will keep the wires from getting shaken off from the battery.
  3. Using a hot glue gun, attach the AA battery to the top of your Scribble-Bot (which is actually the bottom of your recycled container). Allow the glue to thoroughly cool down before handling the Bot.
  4. Cut an unused glue stick in half. Attach a piece of the glue stick onto the metal arm of the DC Hobby Motor by pushing the metal directly into the un-melted glue stick. The motor should not be attached in the exact middle of the glue stick, but about ¼ of the way down.
  5. Carefully glue the DC motor onto the top of your Scribble-Bot (be careful to not cover any copper tabs that may be on your motor! We will need to attach wires to them later!). You could either place the motor upright on the top of the Bot OR you could glue the motor sideways, making sure the glue stick arm hangs far enough over the side of the top of the Bot to freely spin. Allow the glue to thoroughly cool down before handling the Bot.
  6. Using Duct tape, secure 3-4 Washable markers around the sides of your Scribble-Bot. The (capped) marker tips should face downward, and all makers should be evenly spaced and leveled.
  7. Now get creative! Decorate your Bot using Googly Eyes, paint, glitter, construction paper, or anything else to make your Scribble-Bot look awesome!
  8. Once your Bot is fully decorated, it’s time to test it out. Place a large sheet of white paper on a clear, flat surface. Remove the marker caps from the Bot’s legs and set them aside.
  9. Carefully attach one of the Alligator Clips to one of the tabs coming from the DC Hobby Motor. Do you notice any movement? Why or why not?
  10. Carefully attach the other Alligator Clip to the other motor tab. Why do both wires need to be attached before the Bot turns on?
  11. Set the Bot on the center of the white paper and watch as it creates a unique piece of Modern Art before your eyes! (You might need to guide the Bot back onto the paper from time to time, as the Bot will likely wander off…but that’s why it’s important to use WASHABLE markers!)
  12. When finished, unplug both Alligator clips from the motor and secure all marker caps. Wash up any stray markings made around your paper. Most importantly, be sure to hang your Scribble-Bot’s masterpiece in a prominent location!
scribble bot 3

HOW DOES IT WORK:

Electric Motors are used in many different electronics today. They can be found in electric cars, planes, trains, elevators, kitchen blenders, ceiling fans, computer disk drives, electric toothbrushes, vacuum cleaners, washing machines, electric toys, and even in your cell phone to make it vibrate when a friend calls! In each of these cases, the motors use electrical energy to create mechanical energy that can be used to rotate, vibrate, or drive an object. The arm of the motor (called the Drive Shaft) spins around when the motor is connected to the battery by a closed circuit of wires. A circuit is a closed conductive path that allows electricity to flow from a power source (like our AA battery) to run an electric appliance. If any one of the wires comes undone or is unplugged, the circuit can no longer allow electricity to flow and the motor will not run.

Because we attached an unbalanced weight to the Drive Shaft, the spinning weight will cause the Scribble Bot to continuously tilt from one side to another, causing the Bot to jitter around and seem to move on its own. This motion is especially visible when we attach markers to the Bot.

THE MORE YOU KNOW:

Motors come in many shapes, types, and sizes. An especially large and powerful electric motor is now responsible for driving the largest truck in the world! The GVW BelAZ 75710 is a Russian mining truck that weighs a whopping 800 tons (1,600,000 pounds) when it is fully loaded. The truck is so massive that it requires four giant electric motors to get it running!

On the other hand, Engineers at the Cockrell School of Engineering at the University of Texas have recently designed and built a type of “nanomotor” that is 500 times smaller than a grain of salt. The microscopic drive shafts can spin 300 times every second, making them faster than a jet engine! Scientists hope that these nanomotors can help to deliver medicine to precisely targeted parts of the human body.

GOING ONE STEP FURTHER:

  1. Experiment using different coloring tools as feet for your Scribble-Bot (Markers, Chalk, Crayons, Pencils, etc). Which ones work the best? Which ones work the least? Can you explain why?
  2. Try out different types of weights for your motor arm (Glue Stick pieces of different lengths, a Clothespin, a rubber Cork, a blob of modeling Clay, etc).
  3. Or try re-placing the same glue stick arm so that it is now more centered on the Hobby Motor. Does the Scribble-Bot move around more or less when the glue stick is centered? Why or why not?

Build your custom Bot, and start Scribbling this Winter Break!