Hello MMD'ers,  A more safe way to power the 110 Volts DC motor
is to insert a lamp dimmer, with the appropriate current rating,
before the diode bridge.  Light dimmers are very inexpensive today.

Connect also, as a test indicator, a light bulb across the output.
Compare the light intensity of the lamp with one of the same power
rating connected to the mains voltage.

The spin-off of this circuit is that you can vary the speed of the
motor.

Still, the motor might overheat if the iron core is of solid steel
instead of laminated, due to the remnant ripple current.  So, from
time to time, feel if the motor is not overheating.

Kind greetings from the Netherlands,

Willy van der Reijden