Permanent Magnet Experiments: Pulse Motor Lift with Magnets Underneath Rotor

Hook

I pulled the permanent magnet stator off the pulse motor and tried lifting the whole rotor with magnets underneath. The difference in coasting time is wild.

Watch this experiment

Six-coil reed switch drive, stacked 10-inch discs, and a floating magnet array underneath — all running on the bench with nothing but a wrist flick to start it.

What you'll learn

How a bottom disc loaded with permanent magnets creates actual lift, what happens when you remove a ring of magnets, why the motor sometimes sounds loaded even after power is cut, and how bearing choice and center of gravity affect run time.

From the bench

The circuit still fires in the exact same order — here, there, there, here, there, there — even though it’s happening at light speed. With the stator permanent magnets gone the rotor coasts for over a minute on a light spin. Last time a green wire was draped across the red ones and that created a real circuit-inside-a-circuit load. Straightening the wires fixed it instantly.

The rotor is six 10-inch discs glued together. Each disc is about 3/16 inch thick so six give me just over an inch and a quarter — perfect for the gap I needed. Bearings sit on the top disc and bottom disc with basically empty space between them. That cuts friction compared with stacking bearings directly on the shaft.

How it works / what we changed

I added a lower carriage with a flange at the very bottom. Everything above that flange is being lifted by the opposing fields of the permanent magnets on the bottom disc. You can literally see the upper assembly floating higher than the pegboard surface. The pegboard itself is soaked with old WD-40 around the shaft hole so it’s a little soft — that might explain why one side sits higher than the other.

magnetic levitation

The bottom disc with two full rings of neodymium magnets lifts the main rotor by the thickness of the flange plus a bit more. When I took one entire row of magnets off, the rotor dropped and the gap closed on one side. It still levitates but the wobble increases because the shaft sits lower in the softened pegboard hole.

pulse motor lift

You can watch the entire upper carriage rise when the bottom magnet array comes into range. The lift is strong enough that the top bearing is no longer resting hard on anything. This gave the longest coast times I’ve seen on this build — over ninety seconds from a gentle push.

magnets underneath rotor

Placing the magnet array directly underneath changes everything. The fields push up instead of fighting sideways like a normal stator. I tried aligning the lower ring with the drive coils but the height was off after removing a row. The lift is uneven because the pegboard hole is disintegrating on one side.

reed switch pulse motor

The reed switch is still triggering off the same rotor magnets. You hear a distinct tick every time a magnet passes. When the motor is powered down that ticking continues for a second or two because the rotor is still spinning past the switch. That sound can easily be mistaken for mechanical load or bearing noise.

magnetic friction

There is audible friction between each magnet node even with the levitation disc. It’s less than stacking extra bearings on the shaft though. I’ve tried both methods on camera. The disc method wins for long coast times but the loose magnets can rattle once speed drops.

pulse motor load

Several times the motor sounded like it had a heavy load. Even after cutting power the noise continued. Turns out the bottom magnets were rattling against the disc. Removing the disc entirely made the slowdown feel worse — maybe more friction from the bearings now carrying full weight, or the lower center of gravity changing resonance. I never found a wiring fault.

Bedini style motor

This six-coil setup is running in the classic Bedini style but without the usual permanent magnet stator. The circuit still recovers energy and the rotor freewheels nicely once the stator magnets are gone. It’s a good reminder that the permanent magnet placement is doing a lot of the work in a standard Bedini SSG.

neodymium magnets pulse motor

All the lift and drag you see comes from strong neodymium magnets. I could glue them down to kill the rattle or add three more coils in the open spots for generation. The current setup still has three empty positions on the rotor — plenty of room to experiment with generator coils or extra drive coils.

Builder checklist

• Check every wire crossing after changes — one draped wire can create a hidden load.
• Measure lift gap with the motor off and on.
• Listen for continued noise after power is cut — that’s usually magnets rattling, not electrical load.
• Try both bearing stacks and levitation discs — log coast times for each.
• Secure magnets before high-speed runs.
• Keep the pegboard dry — WD-40 softened the shaft hole and created wobble.

Troubleshooting

Rattle after power-off almost always means loose magnets on the disc. Slow coast-down without the levitation disc points to bearing friction or changed resonance. Uneven height usually traces back to a worn or soaked mounting hole. If it feels loaded, watch the green and red wires — they cannot touch at two points.

Safety

Strong neodymium magnets can pinch fingers hard. Keep loose magnets away from the spinning rotor. The spinning disc can shake the table — secure your setup. Reed switches can stick at high speed; watch for overheating if you add more coils.

FAQ

Does the lift actually reduce friction? Yes — coast times increased dramatically once the upper assembly was floating on the magnetic field.

Why does it sound loaded after power is cut? The magnets on the disc keep rattling against the plastic even though the circuit is off.

Can I add generator coils in the empty spots? Absolutely. The transcript shows three open positions where pickup coils could harvest back EMF or induced current.

Is this the same as a Bedini motor? Close — same circuit family but the stator permanent magnets have been replaced by the levitation array underneath.

Should I glue the magnets? If rattle appears at low speed, yes. Otherwise the disc is easy to swap for different experiments.

Related on this site

• How to Build a Pulse Motor: Parts, Coil Gap, First Spin
• Pulse Motor Rotor Design: Magnets, Materials and Balance
• Magnets Cause Friction — Full Version
• Magnetic Levitation on a Pole – Experiment 1
• I Finally Got My Pulse Motor Running (Reed Switch)

Watch this experiment on YouTube

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