Shaded pole motor, 2500rpm

To get a 0.25" shaft might mean looking in old electrical equipment.

Many (many) years ago there was a way of getting a 2:1 speed switch with 4-pole motors which had a coil on every pole.

For 1500 rpm (off load) the coils were energised in a N-S-N-S 4-pole configuration and for 3000 rpm (off load) the coils were switched to a N+N-S+S configuration, to get an effective 2-pole motor.

Any chance with your present motor?

Notice the 'off load' distinction. These shaded pole motors do run with a large slip on load, and your '1250 rpm' 4-pole motor is really a theoretical 1500 rpm sync speed motor running at 17% slip.

Router collet shim from a cheap router 8-)

Along with grinding the 6mm cutters into trammel points or doorstops, it also helps to reduce the risk of ever using one of these dangerous

Hi,

If you can only get 6mm then a couple of layers of ali from a coke can might shim it out OK.

cheers, Pete.

I've got a box full of unused 30 year old ones made by ECM Motors of Schaumburgh with 0.25" shafts, however, all have reduction gearboxes giving 200RPM at the end. Perhaps you could transpose the rotor from yours and build one out of the bits you have plus one of them? What are the dimensions of the one you have?