Donut Magnets Outside Poles — Opposing Ring Magnets Extend Spin

Hook

I finally put donut magnets outside poles on the lower disc and gave the top disc one tiny flick. It kept spinning for over a minute and a half, with a clear magnetic push each time it passed a ring. Something real is helping it along — and it is all about orientation and balance, not hype.

Watch this experiment

Right from the start you can see the top eight-inch disc floating above the bottom one with nothing in between. Three donut magnets sit on the outer edge of the lower disc, all oriented the same way so they push instead of pull. I give the top disc a little nudge and it starts rotating. The motion lasts longer than I expected from such a small flick.

What you'll learn

• How three donut magnets on the outside create a series of repulsive kicks
• Why magnetic rings (donut/ring magnets) work well as fixed outer poles
• How magnet pole balance decides whether the disc rides smooth or wobbles
• Why ring magnets opposing each other extend spin time but still cannot make perpetual motion

From the bench

I used two eight-inch discs, three strong donut/ring magnets on the outside, and later a rectangular magnet on the top disc for a second test. Everything sat on a normal workbench. The magnets are strong enough that you feel the push before they line up. After a light flick the top disc ran about one minute and forty-five seconds before it was too slow to keep useful motion.

How it works / what we changed

The donut magnets are all opposing, so a moving magnet on the top disc gets a repulsive kick each time it lines up with one on the bottom. You can see the little speed bump at each pass. I tried a bigger rectangular magnet on the spinning disc for a stronger interaction. That gave a bigger initial spin but made the whole stack wobbly because the mass was only on one side. Even with the imbalance, the push points still showed up.

Donut magnets outside poles setup

Placing the rings on the outside poles of the lower disc keeps the interaction out near the rim, where lever arm is longest. That is why a small wrist flick can still produce a long, interesting spin. It is not free energy — it is stored kinetic energy plus timed magnetic pushes fighting friction and imbalance.

Builder checklist

• Two matching 8-inch discs that can float or spin freely
• At least three strong donut/ring magnets for the outer edge (all same face orientation for push)
• One or more smaller rectangular magnets for the rotor (balance them opposite each other if you can)
• Flat, level surface so gravity does not pull the stack off center
• Notebook or phone timer for each run (seconds until it dies)

Troubleshooting

If the disc dies quickly, check that every donut magnet is oriented for push, not pull. An off-center magnet creates wobble that kills momentum. With only one rectangular magnet on the top disc I was slightly out of balance, but the magnetic push still helped past sticky spots. Ordering three more donuts for a two-one-two-one pattern around the rim is the next experiment to smooth the slowdown between kicks.

Safety

These are powerful neodymium-style donut magnets. Keep fingers clear when the disc is spinning so you do not get pinched. Work on a stable bench so nothing flies if the disc jumps. Keep loose tools and other magnets far enough away that they cannot snap together.

FAQ

Can this become perpetual motion? No. Anything stationary still needs that initial flick, and friction plus imbalance always win eventually.

Does gravity help or hurt? It depends. A smaller disc under a larger one uses gravity in the stack, but whether that helps spin time is still something I am testing.

Why did it look like it sped up sometimes? When the moving magnet lines up with each outside donut you get a visible push — a kick — before friction takes over again.

Should I order more donut magnets? I ordered three more so I can try alternating placement around the edge and compare spin times side by side.

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
• Understanding Magnetic Friction in Pulse Motors

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