Your grandmother means well. But by the time she figures out something’s a fad, it is old news. So maybe you got a fidget spinner in your stocking this year. Beats coal. Before you regift it to your niece, you could repurpose it to be a motor. Technically, [B.Aswinth Raj] made a brushless motor, although it isn’t going to fly your quadcopter anytime soon, it is still a nice demonstrator.
You can see a video below. The idea is to put magnets on the spinner and use an electromagnet to impart energy into the spinner which is on a piece of threaded rod left over from your last 3D printer build. A hall effect sensor determines when to energize the electromagnet.
A brushed motor uses a spring-loaded brush to carry current through to the motor’s coils and keep the magnetic field oriented properly. A brushless motor works differently. There are several schemes that will work, but the one [Raj] uses is the most common. He adds fixed magnets on the rotor then uses an electromagnet to provide the correct push at the right time. A practical brushless motor will likely have more than one coil, though, and the controller has to do a particular sequence to move the rotor around the rotation.
If you want to see the insides of a real motor, we looked at how to rewind them earlier. If you’d rather repurpose your spinner to something more practical, you could always make some music.
Easter egg: if you skip into the video on youtube.com, the loading animation will be a fidget soinner, too!
Love the headline…. ha… ha…!
Credit to our editor for the title.
I have no intuition for motors. I would have thought the proximity of the hall effect sensor to the electromagnet would swamp the sensor, and i would have placed the sensor 120 degrees away so it was only sensing the permanent magnet field,
I assume that the sensor readings are timed to not be measuring while the electromagnet is on.
As a joke a couple of years ago I gave my nephews a lump of coal each for Christmas ( their Mum told me they had been bad and didn’t deserve anything). It backfired, they had never seen coal before and thought it was great!
So I guess coal beats fidget spinners ;-)
Same…
I would have to give ashes, because all the kids I know would light it on fire.