Ignoramus8975 writes:

Tim, how can I test it? Can I, say, make it produce, say, 15 amps of
current, and I would watch the voltmeter to see if it sags a lot?

Look, if you're using digital encoders and controllers, the DC input does
not have to be regulated, and a gutsy toroid plus fullwave bridge and a
modest capacitance is fine. The digital servo controller is itself a
regulator by nature. The input DC can sag and ripple as long as you have
enough volts there to meet the speed demand and current for the torque
demand. The controller's digital feedback loop responds much faster than
any sag or hum frequencies.