Shaded pole motor, 2500rpm

[Ian White]

Please can anyone help me find one of these? It looks similar to

but maybe with a deeper stack of stator laminations.

Two small complications:

• It must be 2500rpm nominal (it's to replace a 1250rpm motor)

• The shaft needs to be 0.25in diameter (not 6mm) and about 2in long.

These used to be bog-standard items, but they all went to hide when they saw me looking.

AIUI there is no way to modify the existing 1250rpm motor, because the speed is determined by the number of 'poles' in the rotor construction.

[Tony Williams]

2-pole shaded pole motors are readily available, but only with a 6mm shaft these days.

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.

[Andy Dingley]

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

6mm cutters in your 1.4" collet.

[Pete C]

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.

[Peter Parry]

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?