I am in process of building an Arduino based motor controller with similar functionality as in MRI motor controller. As part of that development, I was observing the differences between the Neverest motors. Those differences could be relevant for some FTC developers.
I used the following motors:
Motor Ratio Gearbox
AM-3461 1:3.7 Planetary
AM-3104 1:1 None
AM-3102 1:20 Classic
Using the Arduino Line Plotter, I was observing the speed changes as recorded with 10 ms measurements for 5 seconds. There was no load for the motors. The speed was recorded as a frequency of interrupts directly from the encoder output wires. The interrupts were for all transitions
- Rising A
- Falling A
- Rising B
- Falling B
An internal 2 MHz reference counter was used for the measurements. Here is the summary of the observations:

The conclusions are:
AM-3104 and AM-3461 share the same or similar motor. AM-3102 has a different encoder with higher resolution. The new AM-3461 seems to have the highest quality. It had the lowest mechanical disturbances. The AM-3104 had the worst disturbances.
These motors are specified for nominal 12V usage, but they can be used at 20V as shown in these results. The AM-3461 can run even at low voltage, such as 0.3V. The other two motors need 0.7V to keep the motor running.
Please let me know, if you want to see the waveforms behind these measurements.
Cheers, Ollie
I used the following motors:
Motor Ratio Gearbox
AM-3461 1:3.7 Planetary
AM-3104 1:1 None
AM-3102 1:20 Classic
Using the Arduino Line Plotter, I was observing the speed changes as recorded with 10 ms measurements for 5 seconds. There was no load for the motors. The speed was recorded as a frequency of interrupts directly from the encoder output wires. The interrupts were for all transitions
- Rising A
- Falling A
- Rising B
- Falling B
An internal 2 MHz reference counter was used for the measurements. Here is the summary of the observations:

The conclusions are:
AM-3104 and AM-3461 share the same or similar motor. AM-3102 has a different encoder with higher resolution. The new AM-3461 seems to have the highest quality. It had the lowest mechanical disturbances. The AM-3104 had the worst disturbances.
These motors are specified for nominal 12V usage, but they can be used at 20V as shown in these results. The AM-3461 can run even at low voltage, such as 0.3V. The other two motors need 0.7V to keep the motor running.
Please let me know, if you want to see the waveforms behind these measurements.
Cheers, Ollie