Frame / Scaffold for Battery-Magnet Homopolar Motor

thingiverse

Frame / Scaffold for Battery-Magnet Homopolar Motor **Warning**: Safety first! Observe all safety rules. **Update**: A cone spiral scaffold has been added, which works as expected but requires more copper wire. It also tends to move up and down slightly, presenting a great problem for further exploration. The homopolar motor is an interesting electronic experiment that can be played with. Using an AA battery, some copper wire, and a few neodymium magnets, one can quickly build a working motor for educational demonstration. However, balancing the copper wire frame can be challenging, especially for beginners. This design is a scaffold (45 mm x 60 mm), which allows the copper wire to be easily balanced by pushing it into the grooves. One can focus on the contact between the wire terminals and the magnets. #### Materials Needed 1. An AA battery (rechargeable batteries are acceptable). 2. Approximately 10 inches (240 mm) of copper wires (18 or 20 gauge). 3. A few neodymium magnets (about 15 mm in diameter). 4. A 3D-printed frame. #### How to 1. Push the wire into the frame and secure the ends. 2. Adjust the ends of the wire so that they lightly touch the magnets, completing the circuit. A circular loop is acceptable. 3. Verify that the positive terminal of the battery can touch the wire at the top. 4. If necessary, use a screwdriver to push it out slightly. 5. Be safe and explore electromagnetism. #### Questions 1. Is it a short circuit? Why or why not? 2. How does one change the direction of the spinning wire? 3. What would happen if the magnets are flipped at the bottom of the battery? 4. Why do parts get hot? #### References 1. https://en.wikipedia.org/wiki/Homopolar_motor 2. https://www.ligo.caltech.edu/LA/system/media_files/binaries/270/original/Homopolar_motor_vs2.pdf?1453822070