Electric motors are used in everything from fans to washing machines to scooters. This project will help you picture the basic idea that makes electric motors go round.
Supplies:
Wire—5 feet of “bell wire,” solid (not braided) with a plastic coating. Available in either 18 or 20 gauge, available by the foot at Home Depot or Lowes, or from Amazon (https://www.amazon.com/gp/product/B075TSZRSL/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1)
Ceramic block magnet 7/8 × 1 7/8—sold in pairs at Lowes or on Amazon (https://www.amazon.com/gp/product/B009TKUL7E/ref=ox_sc_act_title_1?smid=A2XO814YXOWTGM&psc=1)
D Cell 1.5 volt battery
Tape—electric or duct tape
Large metal paper clips—2
Modeling clay, putty, or Play Doh
Fingernail polish
Instructions:
Wrap a strand of wire around a broom handle eight times. Slide the wire off. Pinch the coil together. Wrap each end around the coil twice, leaving a few inches of each end pointing straight out on both sides of the bundle.
Bend two large paperclips to form loops in the middle. Straighten the ends. Then bend those ends into short loops.
Tape the paperclips to the ends of the battery.
Set the D-cell battery sideways in a bed of putty with the paperclips standing upright.
Set the magnet on top of the battery.
Place your coil with its ends in the loops of the paperclip. Adjust the paperclip height so that the coil will turn, just missing the battery by about 1/8 inch.
Remove the coil. Trim the insulation from both wire tails.
With the coil standing upright (Important! vertical, not laying flat), use fingernail polish to coat the top half of the bare wire of one tail. Let the polish dry for 20 minutes. Adjust the coil and tails until it spins evenly without wobbling when you hold it in your fingers. Put the coil back into the loops of the paperclips. Your motor may begin spinning on its own, or you may need to give it a push start.
Things to check:
• Nail polish on only the top half of one tail
• Polish applied with coil in vertical position
• Paperclip loops are even.
• Coil turns freely and evenly without wobbling.
• Coil spins close to the magnet.
• Paperclips touching metal ends of the battery.
How it works: Your block magnet is always creating a magnetic field. Your coiled wire is an electromagnet. But only when electricity is flowing through it. When the coil makes a half turn, fingernail polish prevents metal from touching metal. Electricity can’t flow, and the electromagnet coil is turned off. The two magnets work together, taking turns pushing and pulling and keeping the coil spinning.
