Comments on: Motor hums but no torque on inexpensive table top drill press?

By: William B

William B — Sat, 23 Jul 2011 23:11:09 +0000

remove the motor,
take the bottom end off, check the centrifugal switch on the shaft of the motor,
mine did that and the C-switch was stuck cleaned it up with 400 grit sand paper, works fine

By: Dan B

Dan B — Sat, 23 Jul 2011 22:28:31 +0000

If you can turn the motor by hand with little difficulty, then the motor isn’t seized up. The capacitor is probably defective. Or it could be the centrifugal switch hasn’t connected the capacitor to the motor start windings. Check the switch to see if you can operate it. It is located inside the end bell of the motor.

Remove the capacitor and take a look at its condition. You may see some leakage or ‘bloated’ if it is bad – replace it.

By: paul h

paul h — Sat, 23 Jul 2011 22:10:20 +0000

Many small appliance motors have a “start capacitor” which can go bad and cause the motor to just hum and not turn. You might get the motor spindle to turn manually enough to get it going but it’s best to replace the capacitor….they only run 10-15.00. Usually the capacitor is mounted on the side of the motor with some wires going to it but sometimes, it’s a separate unit that looks like a cylinder or oval shape. A bad capacitor will sometimes have a blistered shell or signs of leakage. That would be my guess unless it’s the type of motor that doesn’t use one in which case the motor may have bad brushes or other issues. Then it’s a matter of removing the brushes and checking them for signs of wear or remove the motor unit and having a motor/electrical shop repair it…or replace it.

By: sensible_man

sensible_man — Sat, 23 Jul 2011 21:22:06 +0000

Remove the belt guard and turn the pulley by hand. It may just be froze up from non use.

By: stretch

stretch — Sat, 23 Jul 2011 20:37:40 +0000

Skip,

If motor hums, its getting power. If no torque, it may be worn gears. Remove housing and check for worn or damaged teeth, etc on the gears, especially if the motor has a worm gear. If it’s a split-phase motor, the centrifugal switch prevents windings from burning out by cutting power to them. check the contacts to see if they are working properly. If you have a pulley system, check the drive belt, it may be broken or extremely loose.
You can usually “smell” a faulty motor before serious damage is done. A mild odor of hot oil, metal or plastic usually means that the motor is overheating, a problem often caused by overheated winding insulation or by friction in the motor bearings or drive components. Lubrication may solve the problem. But if the windings burn and short internally, the charred plastic insulation will emit a pungent acrid odor and the windings may have to be replaced.
Also, check your motor to if the gears are clogged, the belt is too tight or the bearing(s) are dry.

This is just some of the commons trouble-shooting tips, you may find something else once you remove the housing for inspection.

Good luck and hopefully it’s nothing serious.