Issue:
I have built the Crane X7 arm, a 7-axis arm using primarily XM430-W350 motors. For now, I am testing it with Dynamixel Wizard and one of the motors cannot maintain a position for more than about 10 seconds. An overload error is indicated (but I can’t tell the reason). At the time of the error, the temperature reaches about 51C (the limit is 80), which interestingly is about 10+ C higher than other motors in the arm pulling comparable current.
Please see this video of the problem: https://youtube.com/shorts/EmT07lKvbac?feature=share
If you look closely you should see the current and temperature values in the top right as the arm fails.
Note also you can hear some motor noise which I believe is this motor. There is also a fan continuously running but the noise should be discernible above it.
Maybe this can help isolate the problem?
If this is a bad motor I would like to know so I can replace as soon as possible. I encountered this issue with one other motor but I haven’t been able to replicate yet.
Any troubleshooting tips would be much appreciated! It’s quite a simple setup. The motor running 10C hotter than others is weird to me.
UPDATE:
I’ve noticed that multiple motors experience large current fluctuations with only very slight position changes. For example, if motor torque is on and I push on the motor, it might move by a degree or less, and the current can increase from ~50mA to ~600-700 mA. Note I am not pushing on the joint but rather nudge it and let go. The same effect can be seen when moving the position through the Wizard. Certain specific angles will cause large spikes in current. It’s not simply the orientation (e.g., even some orientations that are stable at rest can result in current increases). Here is a video: https://youtube.com/shorts/ZC3tnihAGx4?feature=share
Is this normal?
DYNAMIXEL Servo:
XM430-W350-R
DYNAMIXEL Controller:
U2D2 and SMPS converter board for power.
Software Interface:
Dynamixel Wizard