3 ms·

You’d also need to make magnets, know their polarisation, create bearings, and have the skill to assemble all of that as well.

• WalterBright 7y ago
  None of that is necessary. I built a working electric motor in cub scouts using several feet of wire, tape, some iron nails, some sheet metal cut from tin cans, a wood board to mount it on, and a battery. Tools required: tin snips and a hammer. A battery can be made from a jar, lemon juice, and two electrodes. Believe me, as an 8 year old, my skills were limited to using a hammer to mash my thumb with. :-) Electromagnets substituted for magnets, and bearings were a dent in the sheet metal that the point of a nail sat in and turned. Simple and effective. Once you showed this to a medieval craftsman, they could reproduce it and start improving it.
  • pushpop 7y ago
    I’m both impressed and have learned something new. Thank you :)
    • WalterBright 7y ago
      I found a variant that uses magnets: https://www.bu.edu/gk12/tommy/Electric_motors.pdf https://www.bu.edu/gk12/tommy/Electric_motors.pdf The version I built was far simpler, and used electromagnets instead of the magnets, but you can see the general idea. I didn't design it, I don't know where the Den Mothers got the design from. But I found it fascinating, as you could see and feel how it worked. I built several of them. One day, I got a little bolder and replaced the battery with an A/C cord. The motor buzzed loudly and burst into flames. I learned about alternating current that day :-)