I Spun a Magnet Disc for 8 Turns With One Nudge (Magnetic Friction)

Hook

I gave this floating magnet disc one little nudge and it went around eight times. Not bad for something I just threw together on the bench. The secret is the space created by magnet levitation — it cuts friction way down.

Watch this experiment

I stacked donut magnets on a central pole with a plastic disc underneath to keep everything centered. Without that disc the whole thing would tilt and rub. You can see the bouncy gap all the way around — plenty of room but not so much that it flops. I gave it a spin and counted the rotations while it slowed down. Even a gentle wrist flick produced multiple turns thanks to the weightlessness effect of levitation.

What you'll learn

You'll see exactly where friction comes from in a setup like this, what the coils picked up when wired to a capacitor, and why magnet levitation diy might be one of the easiest experiments to try first. All numbers and observations come straight from what happened on the bench.

From the bench

The central pole touches the disc, so that's one friction point. The big donut magnets below create spaces that the small rotor magnets pass through — each pass adds a little magnetic tug. No bearings yet means some wobble, and that wobble creates more drag. The outer poles on the coils are magnetic too, which adds another small force. I didn't push it hard because too much speed makes it flop around.

How it works / what we changed

The plastic disc keeps the stack centered so the magnets stay aligned with the pole. That gives even space all around instead of lopsided rubbing. Levitation lifts most of the weight off the pole, leaving only light contact. One nudge is enough because there's less friction to kill the momentum. I plan to add bearings next to see how many more rotations I can get.

Magnet magnetic motion

The magnet magnetic motion here is pretty simple. The whole stack floats on the pole with visible gap. That near-weightless state lets it keep spinning after a single light push. Even though I didn't give it much thrust, the disc completed eight full turns before slowing. The motion lasts longer because friction is mostly removed by the levitation effect. It's a great way to feel how magnetic fields can both support and resist movement at the same time.

Coil def

I wired several coils together, added a 2.7 volt capacitor, and hooked them to a multimeter. The coil def (as in the capacitor acting as capacity storage) showed a very small amount of micro voltage just from being connected while the magnets moved past. It wasn't huge, but it was enough to notice on the meter. The coils sit near the spinning magnets and pick up a tiny bit of energy each pass. I kept saying "capacitor" after almost slipping and calling it a cap acity — old habits.

Magnet levitation diy

Magnet levitation diy doesn't have to be complicated. This version uses a central pole and stacked donut magnets with a centering disc. The space between the rotor and the base magnets creates the lift. It's bouncy, which tells me there's room to add a little more weight — maybe another disc — before it bottoms out. Levitation is probably one of the easiest and best starting points for these experiments. I still need to add bearings to the discs to really see how long it can spin, but the first tests already look promising.

Builder checklist

• Central pole straight and smooth
• Plastic or non-magnetic disc for centering
• Matched donut magnets for base and rotor
• Even gap all around the stack
• Optional coils + capacitor for basic pickup test
• Bearings ready for next version

Troubleshooting

If it tilts and rubs, the centering disc is too small or the pole is off. Too much wobble means the stack isn't balanced or the magnets aren't centered. If it stops fast, check for strong magnetic drag from the outer coils or donut spaces. Micro voltage too low? Make sure the capacitor is connected and the coils are wired in the right polarity.

Safety

Don't spin it crazy fast — it can flop and magnets may fly off. Keep fingers clear of the spinning stack. The voltages are tiny but still treat capacitors with respect after charging. Work on a stable surface so nothing gets knocked over when the outer poles tug on nearby tools.

FAQ

How many turns did you get? About eight from one gentle nudge.

Did the capacitor really show voltage? Yes, a very small micro voltage reading appeared on the multimeter.

Do I need bearings right away? Not for the first test, but they will reduce friction even more.

Can I add more weight? A little — maybe another disc — but watch the gap close.

Related on this site

• How to Build a Pulse Motor: Complete Beginner's Guide
• Pulse Motor Rotor Design: Magnets, Materials and Balance
• Magnetic Levitation with Six Donut Magnets
• 7+ Minutes of Motion: Magnetic Disc Spinning With Just a Wrist Flick
• Levitation & Electricity — Coil Demonstration

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