The z-axis, when driven downward, was causing the power supply to click and an amber LED to light. I made this quick video to send to Teknic to ask if this was due to regen (I originally thought my z-axis was binding, but addressed that), and they came back and explained this was due to regen from the servo. For more details, see
https://questionable-engineering.com/blog/ballscrew-woes
