XC330-T288 - High Idle Temperatures

Support Hardware Support
21

Just to add another datapoint, I bought a single replacement XC330-T288 to replace “102” while the warranty issue is sorted, in exactly the same position on the arm with all the same ventilation it’s sitting at 29c after 15 minutes. The other T288’s still warm up to previous amounts, the servo in the mirror position on the other arm (110) is sitting at 57c.

[16:51:41] : {100: 42, 101: 44, 102: 24, 103: 40, 104: 17, 105: 16, 106: 16, 107: 17, 108: 43, 109: 47, 110: 46, 111: 41, 112: 16, 113: 16, 114: 16, 115: 16}

[17:7:4] : {100: 49, 101: 54, 102: 29, 103: 48, 104: 18, 105: 18, 106: 18, 107: 19, 108: 51, 109: 59, 110: 57, 111: 49, 112: 18, 113: 18, 114: 18, 115: 18}

I’ve no idea what is wrong with these other servos, there’s certainly something not right though.

22

Just to close this thread off, they were confirmed as faulty and replaced. The new ones sit at around 25-28c idle which seems much more reasonable.

1 Like
23

Sadly, the new servos have started overheating. The ones that were replaced… One of them seems to have burned out and it’s not responsive in any way either.

The only thing I did differently was to increase the voltage to 11.8v to test using the same circuit for another device that needed 12v. I ended up changing it back to 11.1v shortly after, probably 20 minutes or so.

The specifications for these servos state 6.5v - 12v, running them at 11.8v can’t have caused this can it? You haven’t got an issue with voltage regulators in this model do you as it’s starting to look like it?

image
image806×196 11 KB

24

Running the same script as before these are the temperatures with a desk fan directed at the robot

image
image1906×257 37.8 KB

Worth noting that servo 102 is running at 27 degress, this is the spare servo I bought before for testing that wasn’t plugged in when I ran the servos at 11.8V, the servo it replaced appears to be toast.

25

I’ve been working my arse off to get this robot ready for a demo that’s being recorded for TV on Friday, this is an absolute nightmare.

26

A voltage supply of 11.8V is not a problem.
The repeated overheating of the XC330 seems to have another reason.
Overheating while running is most likely a motor problem.
However, if there is overheating only with the power supply, it is damage to the circuit.
Common causes are overvoltage, reverse voltage, short circuit, static electricity, etc.
Some batteries may supply high voltage the moment they are first turned on.
High voltage may be generated inside the XC330 when the XC330 is driven with an excessive backdrive or when rapid acceleration and deceleration are frequent.
If you connect a capacitor with a large capacity to the power supply, you can protect the product from momentary overvoltage.
Check the cable sheath for splits or shorts.
If possible, it is stable to supply a low voltage within the range where there is no problem in driving.

Hope the problem is solved well.

27

In the current situation, if you have a spare servo motor, replacement is the best option.
If you don’t have a servo motor to replace, why don’t you try changing the joint and position with less movement?
Or, in case of emergency, it is also a way to turn off the alarm shutdown and operate it. (If a product with a high temperature works…)

28

I am having the same issue with my XC330 motors (I have XC330-T181-T).

I used AKA-12070 12V SMPS from Robotis shop (voltage was around 11.8V when 10 motors were attached, and 12.2V when only one motor attached).

After leaving the power attached to motors with TorqueOff for about 30 minutes, I came back to the following issue:

  • status LED blinking on several motors (5/10) - blinking was not consistent (different blinking on different motors)
  • Dynamixel Wizard 2.0 used to diagnose motors
  • motors without status LED blinking: high temperature (55-65C)
  • on some motors with blinking LED, was possible to briefly connect (Dynamixel Wizard 2.0 constantly connects/disconnects to motor)
  • no error codes (Hardware Error Status: 0)
  • also high temperature (65C)
  • LED blinking appears to be repeated resetting of motor
  • same blinking occurs if only 1 motor connected
  • attempted Firmware Recovery using Dynamixel Wizard 2.0 on blinking motor
  • Firmware Recovery reaches 10-11% completion and fails
  • left to cool for 24hr, did not resolve issue

One thing I noticed with XC330 vs. XL330 motors, is that when I applied torque/backdriving to XC330 WITHOUT power connected, the red status light would turn on during the torque application. I assumed this was because XC was 181T, and XL was 288T (different gearing ratio → different backdriving behavior). But could it be another electrical issue?

I have a 5V 10A SMPS that I tried connecting to my remaining working XC330. It has ‘low voltage’ error as expected. The temperature slowly rises (35-40C instead of 55-65C) in a similar way. So the idea that some short occurred makes sense, as temperature seems related to supply voltage.

I can confirm that XL330 motors used in an almost identical setup/application do not have any issue (so far).

29

The issue happens when I power the servos and leave them with torque disabled, this isn’t an issue with how much load they’re under.

Also, it’s eight servos that are showing the issue and I certainly don’t have budget to have that many spares.

30

Dynamixel have reached out by email to get these repaired/replaced under RMA directly with them.