magnetic pulleys: Magnets Cause Friction – Full Version

Papa Bale spins a levitating magnet disc on a pole to show real magnetic friction in a simple setup. One light nudge gives eight full rotations thanks to the weightlessness effect. He points out every friction source and hooks up coils to a capacitor for micro-voltage readings.

Key takeaways

• The plastic disc keeps the stack centered on the pole so it doesn't flop sideways.
• Levitation creates noticeable space that cuts friction and lets the disc spin longer from one nudge.
• Each passing magnet near the outer coils and donut magnets adds a bit of magnetic drag.
• Coils linked with a 2.7 V capacitor produced a tiny bit of micro voltage even without strong drive.
• Wobble, pole contact, and outer magnetic fields are the main friction makers in this build.

In this full version I mess around with a floating magnet stack and talk through exactly where the drag comes from. Bearings would help, but even without them the levitation effect is obvious. One wrist flick and it keeps going way longer than you'd expect on a normal surface.

From the spoken experiment

The following notes stay close to what was said in the video about magnetic pulleys:

> uh what's up everybody uh I'm just making a short video here to show you the power of these magazine this is the thing you see this this disc underneath the magnet is keeping it centered around the pole otherwise it would be all lopsided and stuff so you need one of those you need something to Keep It Center without you holding it there you know um but I mean look at how much space there and it's bouncy which means there's a lot of space there for weight to be applied but not not too much weight I mean you can put maybe another one of these discs on top so let's give it a little spin foreign [Music] magnet magnetic motion say levitation is going to definitely probably be um one of the easiest ones you can do maybe one of the best ones you can do too I gotta get some bearings in these discs to find that out but um yeah it should be really interesting well thank you I mean that just went a…

Builder checklist

• Confirm trigger/sensor timing before chasing higher voltage
• Watch heat on coils and transistors during longer runs
• Record voltage and behavior at each change (one variable at a time)

Related on this site

• Pulse motor resources & glossary
• Start here if you're new
• Back EMF guide
• How to build a pulse motor

Related on this site

• 7+ Minutes of Motion: Magnetic Disc Spinning With Just a Wrist Flick — Similar long spin from light nudge using magnetic levitation
• Levitation & Electricity — Coil Demonstration — Shows coil output during levitation similar to the capacitor test here
• Pulse Motor Rotor Design: Magnets, Materials and Balance — Covers balancing and centering magnets on a pole like the disc used
• Magnetic Levitation with Six Donut Magnets — Directly related donut magnet levitation experiment

---

*Generated from video transcript (hash `7dc0f1c6e9a9…`).*