6+6 Offset Magnet Rotor Pulse Motor (205V Bench Test)

Hook

I spun up the pulse motor with six magnets on top in a hex spread and six more offset on the bottom with opposite polarity. Every time a magnet passes the reed switch you can see exactly how it changes the coast and the voltage climb.

Watch this experiment

Right from the first spin the rotor looked immaculate. Voltage rose slower than with twelve magnets but still reached nearly 200 V. A small reed-switch tweak pushed it to 205 V before I backed it off.

What you'll learn

You’ll see how six-plus-six offset magnets behave, why counterclockwise rotation works better with the cores, and what happens to coasting when the reed switch fires every time a magnet passes.

From the bench

The top six magnets sit in a clean hex pattern. Underneath, the second set is north-south opposite the top ones and deliberately offset so the sensor reads them as staggered. I used the same two active coils that push counterclockwise. The cores still make a brief stop but it’s less noticeable in that direction. A big starter capacitor (1,000 to 12,200 microfarad, 110-125 volt, 50-60 hertz) gives the initial kick.

How it works / what we changed

With only six magnets instead of twelve the energy and electricity generation climb more slowly and never peak quite as high, yet the spin stays smooth. The offset bottom magnets register differently than a perfect 12-magnet array, letting the rotor coast better in some spots. I adjusted the reed switch on the fly; when it triggers too early the motor loses a bit of free spin.

Six magnet rotor

The reed switch triggers every time a magnet passes when the rotor is closer to the sensor. In the counterclockwise direction it seemed to fire less often at first, giving a nicer coast. When I reversed spin the switch engaged every single pass and the rotor slowed down faster than a 12-magnet setup would have. Getting the spacing right so the pass timing matches the third circuit is what makes six magnets work surprisingly well.

Builder checklist

• Hex-spread six magnets on top, opposite-polarity six offset underneath
• Confirm rotor spins counterclockwise for best core behavior
• Set reed-switch gap so it does not fire every time a magnet passes at speed
• Use 10,000–12,200 µF start capacitor rated 110–125 V
• Check coil spacing matches the six-magnet timing
• Measure voltage and RPM after every small adjustment

Troubleshooting

If the rotor slows quickly, the reed switch is probably triggering every time a magnet passes; move the sensor farther away. Voltage not climbing? Try reversing direction—counterclockwise usually works better with this layout. If the offset bottom magnets feel too weak, nudge them a bit closer while keeping them staggered.

Safety

Keep fingers clear of the spinning rotor. The capacitor holds charge after power is removed—discharge it safely before touching terminals. Eye protection is smart when voltages reach 200 V on a bench setup.

FAQ

Does the reed switch really need to trigger every time a magnet passes?

Not always. In this test the motor ran smoother when the switch stayed quiet during part of the rotation, giving better coast.

Why does six magnets work almost as well as twelve?

When spacing and direction line up with the circuit, six magnets still deliver clean 200 V peaks and strong spin, just with a slower voltage rise.

What does “offset” mean for the bottom magnets?

They sit opposite polarity to the top set and are shifted just enough that the sensor sees them as staggered rather than perfectly aligned.

Related on this site

• How to Build a Pulse Motor: Parts, Coil Gap, First Spin
• Pulse Motor Rotor Design: Magnets, Materials and Balance
• I Finally Got My Pulse Motor Running (Reed Switch)
• Less Is More — Clockwise vs Counterclockwise
• Understanding Back EMF in Pulse Motors

Watch this experiment on YouTube

• ▶ Watch full on YouTube