Problems with XM540-W270-R

I am using a Dynamixel XM540-W270-R servo with the dynamixel_interface package on ROS noetic (available on GitHub). I had set the max torque to 0.35 (where 1.0 represents the maximum torque). I use the servos in current_based_position control.

At first, the servo was stalling for about 1–2 minutes, during which it became noticeably hot. To prevent damage, I changed its position so that it was no more stalling.

However, after turning it off, I noticed that I could no longer rotate the servo by hand as I could before. Additionally, the servo started drawing 2–3 times more current than usual, and its effort values were significantly higher compared to my other XM540-W270-R servos.

In Dynamixel Wizard, I can still control the servo, and it behaves mostly as expected—except for the excessively high current draw (twice/three times the normal current). However, when I try to control it using dynamixel_interface on ROS Noetic, the servo exhibits erratic behavior.

I have a robotic arm with four XM540-W270-R servos, arranged in two daisy-chained pairs. All other servos respond normally, but the previously stalled servo behaves unpredictably:

When commanded, it gets extremely hot.
It takes around two minutesbefore it responds to commands.

Despite this issue, I can still communicate with the servo through Dynamixel Wizard without errors. However, its high current draw remains a concern.

Does someone know if this is fixable and if so how?

This sounds to me like there was some damage to the motor during the mentioned stall condition. 1-2 minutes at full stall is a pretty significant time to stay obstructed.

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Hello Jonathon,

it was not at full stall but at 35% of the max stall torque.