Large DC pancake motor

[fungus]

Got this motor off ebay for £40; its a 1,120w motor at 3000rpm, 100v;







Taking off the nameplate I find its a pancake motor; theres the magnetising wires wrapped around the magnets and a black disc in the middle- no visible windings?




On the back theres a tachometer- mini 4 pole DC generator- 10v/1000rpm. I chucked a bolt into my cordless drill (the middle of the shaft is threaded) and spun it up; checking the tachometer it was spinning at 5.17v / 517rpm and I was getting 15.57v out, indicates theres about 10% slip on the motor; looks pretty high cutin but could be mounted easily with pulleys?

[vawtman]

Hey Fungus

 Thats a cool motor.The first thing i would do is take it apart and see what makes it tick.

 Thats just me though.

[Flux]

I wouldn't unless you have the magic capacitor discharge unit to remagnetise it with those coils. Servo motors are best not taken to pieces if at all possible.

Flux

[vawtman]

Learn somethin new everyday.Thanks Flux

[fungus]

I know what makes it tick- its a pancake motor like at http://www.phys.unsw.edu.au/hsc/hsc/electric_motors5.html

except that the armature is cast in resin...

[JW]

Neat link fungus,

  "Don't worry about the two black wires for the moment."

"Try not to think about the black wire for a moment."

"Let's bring the wire outside the motor,

 and once everything is assembled we zap a gazillion amps through the wire. Think about what direction the magnetic field created by the current through that wire will be in. Perfect! Admittedly it's not a very thick wire to be coping with such a large current (typically several thousand amps), but it's only for a few milliseconds and the wire doesn't have time to complain."

So since the motor doesnt have a nameplate hp, its a servo?

The last time I took-apart a MOSFET, I found three of them in there. needless to say, it never worked again.

Its uttery amazing how much neat stuff is lost and saved by scrap-yards. Its a good feeling to walk thru one, and understand what most of the stuff there is.

JW