Need replacement motor

Hello Richard,
I see you have already replaced the speed control for this drill.
It looks likea nice piece of kit, anyway since the power comes from the switch / speed controller , through the first field winding then the brush on one side of the rotor, through the rotor, through the brush on the opposite side of the rotor, then through the second half of the field winding and returns to the switch (or) neutral, it is easyto check for continuity.
Because it does nothing when you press the trigger it sounds like a break in the motor circuit.
I hope you have checked that the cable itself is not broken internally
this happens very frequently near to the drill, where it gets the most bending and twisting.
Using a multimeter set on Ohms you can place one probe t the output from the switch (make sure that it is unplugged ) the other proe on the return side wiring, you souldget a reading of only few Ohms, if not then you can start to to trace through the individual parts. I will assume here that you have done the same for each cor of the mains cable.
For pictures of universal motors just bing or google (universal motor circuits)

Best regards,
Dave Reynolds.

Most motors of that type have a capacitor that puts the stator out of phase with the rotor. They are capacitor start induction run motors. These also have a centrifugal switch inside near the end ot the shaft to put power to the start winding for a split second to determine the direction of turn and to increase horsepower until it is up to speed. So if it fails to start either the centrifugal switch needs cleaning (or replacement if damaged) or the capacitor needs replacing to give it its original power, or the start winding has failed from overheating. There may be a thermal cutout on the start winding that may need to be replaced if it did overheat. If the start winding burned then the motor would require rewinding or replacement.

most drill presses use a capacitor start motor with internal switching . a variable speed control will not work most rely on step pulleys for speed control. possibly you could have blown your capacitor

try cleaning the pulleys buy a good belt (gates) install belt and make sure you have good belt tension

Try wrapping a thin cord around the shaft many times to allow the shaft to be spun in the normal running direction when pulled. Pull sharply on the cord and turn the motor on--if the starting capacitor is bad, the motor should continue to run until shut off. If there is no capacitor, then the motor uses a start winding and a centrifugal switch to start. The switch is supposed to open when the motor comes up to speed. If you used to hear a loud 'click' when the motor was shut off and slowing down, then you likely have the start winding and switch. If the contacts on the switch become burned and not make contact, then it will display the symptoms you mention. You will need to access one or the other end covers to reach the switch. Hope this helps!

you possibly have a motor that the windings are bad. These windings swell when power flows through them and in turn the swelling presses onto the shaft causing the problem. Also, I would replace the capacitor first in the event it is bad If the motor runs properly then that capacitor is the only problem. If it doesn't cure the fan problem then the motor is going out. If you change the motor the capacitor will also need to be changed anyway so try changing capacitor first. Good Luck hope I helped you some


Dave

the reostat trigger switch would appear to be faulty it would be easier to replace it than to try to repair it

Release the belts and check if you can turn the chuck by habd, if the chuck won;t turn, two things could be wrong, 1) the quill bearings are bad or 2) the shaft that runs down thru the quill could ve rusted causing a restriction, if that's the case, WD 40 should loosen it.

indicates either field windings or armature problem
at 12 years parts will be hard to come by

My guess... bad or broken motor windings. Sounds like it is time for a new motor! Good job with the diagnosing, you have some good skills!