Why isn't my homemade DC motor working?

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SUMMARY

The homemade DC motor project involves two neodymium magnets, an aluminum split ring, and alligator clips connected to a 9V battery. Key issues identified include the necessity for opposite polarity in magnets, sufficient coil turns or current to generate strong magnetic fields, and the importance of a reliable connection between copper wire and aluminum. Additionally, the rotor's mass must be adequate to maintain motion during power interruptions.

PREREQUISITES
  • Understanding of magnetic polarity and how to test it with a compass.
  • Knowledge of electromagnetic principles, specifically coil turns and current requirements.
  • Familiarity with materials used in motor construction, such as neodymium magnets and aluminum.
  • Basic electrical connection techniques, particularly between copper and aluminum.
NEXT STEPS
  • Research how to measure magnetic field strength in coils.
  • Learn about the effects of coil core materials on magnetic field generation.
  • Investigate methods for improving electrical connections between different metals.
  • Explore rotor design principles for maintaining momentum in DC motors.
USEFUL FOR

Hobbyists, engineering students, and DIY enthusiasts interested in building and troubleshooting DC motors.

shwaze
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I am building a two coil DC motor as a project. I have two neodymium magnets, an aluminium split ring, and alligator clips acting as brushes, connected to a 9v battery. For some reason it is not working and I cannot figure out why. Can anyone think of something I may be doing wrong. I can post photos if needed. Thank you!
 
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There are lots of reasons a motor might not work.

The magnets have to be of opposite polarity. Are they? Get a compass and check them or note which way the magnets attract each other.

The coils have to produce magnetic fields that are strong enough and of opposite polarity.
This means you have to have a lot of turns or a lot of current. A 9v battery is unlikely to give much current.

Coils with a soft iron core can generate stronger fields than coils without cores.

You may have a poor connection to the aluminium commutator. Connecting copper wire to aluminium is difficult.

The rotor needs to have as much mass as needed to keep the rotor turning when it isn't getting power.
Simple motors only get power in brief pulses.
 
some photos of your setup may help us to see where the problems areDave
 

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