I just recycled this motor and I would like to use it to generate and charge at 60 V. It’s rated at 6350 rpm at 95 V. It's a brushed DC motor. It has two poles.


  • Is it possible to remove the two ferrite magnets and replace with a multiple of neodymium magnets to reduce the rpm?

My theory is 2 poles 95 V, 6350 rpm; 4 poles, 95 V, 3175 rpm; 8 poles, 95 V 1588 rpm; 16 poles 95 V, 794 rpm; ...

Is this actually possible?

  • \$\begingroup\$ Essentially no. Just build a gearbox. \$\endgroup\$ – Brian Drummond Jan 3 at 22:52
  • \$\begingroup\$ In what I think is only a difference in terminology from @BrianDrummond: maybe in theory, but it's not practical. You'd have to rewire the motor and change the commutation to match, and even then I don't think you'd get much of a voltage increase. If you did get a voltage increase, you probably would not see a power increase -- that's pretty much set by the geometry of the motor, and if you could do better with lots more poles, people would. \$\endgroup\$ – TimWescott Jan 3 at 22:59
  • 1
    \$\begingroup\$ "I would like to use it to generate and charge at 60 V" - at what rpm, and why? \$\endgroup\$ – Bruce Abbott Jan 4 at 2:44

Hm, no.

That motor was designed for exactly the shape of magnet used. You'll practically have no chance replacing that with something stronger.

Then you'll change the cabling, i.e. you'll rip out all the hard-lacquered copper and wind something new. Which requires you to get a different cutout to hold your coils. At that point, you're not replacing something in the motor, you're building a new motor from scratch. Without dedicated machinery or experience!

You'll definitely have no chance of replacing the magnet with something cheaper than just buying an electrical machine that gives you closer to what you want, or an appropriate DC/DC converter.


I agree . The best torque increase & RPM reduction is to use belt, pulley, or chain drive.

This is a common 1~2kW exercise motor and a human can do 40~100W. So with an efficient mechanism , you ought to be able to reduce RPM with a DC-DC 30A speed controller.

If you had any thoughts of using this as a Power generator you are on the wrong track and need to consider matching impedance of source to load to maximize power with RPM and torque.


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