Hi everyone,
I posted another PX4 power system log analysis topic here yesterday, so I won’t repeat that content today.
I’ve been running long-duration heavy-lift industrial multirotor missions and sorting through hundreds of ULog files recently. I noticed a tricky hard-to-tune issue that only shows up on motors with 200+ hours of continuous high-temperature hover work.
When the stator windings degrade from sustained heat, even minor unbalance inside the rotor creates constant low-frequency vibration noise in logs. Standard PID tuning gains can’t fully suppress the frame oscillation, and position-mode drift gets obvious during mapping missions.
I swapped brand-new matched motors onto the same airframe, and the vibration peaks in logs dropped sharply right away. The difference between fresh and heat-aged units is visible in every acceleration plot, even with identical KV and prop specs.
This is purely technical log discussion, no hardware sales or brand recommendations at all. I’d love to exchange experience with other developers & test pilots:
- What vibration peak threshold in ULog do you use as a sign that motors need full replacement for stable survey flight?
- Have you adjusted PX4 low-pass filter parameters specifically to offset vibration from worn BLDC motors? Did it impact flight responsiveness?
- For long endurance inspection craft, do you set mandatory motor replacement hour limits based on your log data?
I’m only sharing observations from parsing dozens of flight logs with degraded motors, all practical tuning & maintenance tips are greatly appreciated.