I took apart an old vacuum cleaner with 12 amp motor, made for U.S. 60 Hz AC household use so I could experiment with turning the universal motor into a generator. I know it's a universal motor because applying 12 volts from a battery will get the motor to turn, same direction regardless of battery polarity. I wanted to experiment with it as a generator, so I used an electric hand drill to turn the motor's shaft (quarter inch shaft fit right into the chuck) and connected a car taillight bulb to the blades on the plug. Spinning the motor didn't light up the bulb, so I touched a twelve volt battery to it to get some juice going and set up a field in the motor/ generator. The bulb went out as soon as I took the battery away, so that was no good. I tried this turning the shaft in both directions, and with a much smaller bulb that draws less than 100 mA at twelve volts. Perhaps the hand drill is just too slow.
First question: Would this experiment likely work if I turn the motor several thousand rpm? Second question: Which direction should I turn it?