Technology Forum Has Moved!

The FIRST Tech Challenge Technology forum has moved to a new location! Please take a look at our forum blog for links and instructions on how to access the new forum.

The official blog of the FIRST Tech Challenge - a STEM robotics programs for students grades 7-12.

Note that volunteers (except for FTA/WTA/CSA will still access their role specific forum through this site. The blog also outlines how to access the volunteer forums.
See more
See less

Andy Mark Motors

  • Filter
  • Time
  • Show
Clear All
new posts

  • Andy Mark Motors

    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