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Harper
05-29-2015, 10:27 AM
We have problems with multiple servos on our robot. First, two of our servos, 1 and 8, are failing to respond. They show dashes on the rme program, and in the dxl monitor are shown as failed. Second, servo 11 is also failing to move, but it appears as fine on rme and the dxl monitor. Servo 11 also flashes its LED whenever it tries to move, but 1 and 8 do not. Finally, servo 16 was seemingly working fine, but when we ran the stand up action in rme it made a lot of noise and started moving out of control, and made some snapping sounds; after that the motor is limp, seemingly disconnected inside, and when it tries to move it makes noise as if it is moving inside but the outside does nothing. Also if it is moved externally while powered on it tries to retain its position and makes noise until it is moved back into place but does nothing. I think #16 is probably broken beyond repair, but I'm not sure. Any suggestions?

tician
05-29-2015, 11:12 AM
Sounds a bit like 1 and 8 are possibly having ID conflicts (connect each one individually to arbotix-pro or USB2Dynamixel and perform a search), where servo 8 might have been inadvertently reset to default settings with ID==1. Other possibilities are loose/damaged cables, intermittent shorts in cables, and the very unlikely 'damaged TTL buffer' (never had an AX servo fail like that; plenty of MX died like that, but never AX).

Servo 11 with the flashing LED is being overloaded. It is possible the motor or H-bridge have been damaged so that any attempt to move will always fail, but it is more likely that the servo is getting caught on a cable or frame that triggers an overload when attempting to move and failing to do so.

Servo 16 was driven to self-collision and has likely destroyed its gearset. Replacement kits are ~$6 for AX-12A (http://www.trossenrobotics.com/p/ax-12a-18a-gear-set.aspx) and ~$10 for AX-18A (http://www.trossenrobotics.com/AX-18A-Gear-Set.aspx) in the trossen shop, and are quite easy to replace.

DresnerRobotics
06-02-2015, 09:22 PM
We have problems with multiple servos on our robot. First, two of our servos, 1 and 8, are failing to respond. They show dashes on the rme program, and in the dxl monitor are shown as failed. Second, servo 11 is also failing to move, but it appears as fine on rme and the dxl monitor. Servo 11 also flashes its LED whenever it tries to move, but 1 and 8 do not. Finally, servo 16 was seemingly working fine, but when we ran the stand up action in rme it made a lot of noise and started moving out of control, and made some snapping sounds; after that the motor is limp, seemingly disconnected inside, and when it tries to move it makes noise as if it is moving inside but the outside does nothing. Also if it is moved externally while powered on it tries to retain its position and makes noise until it is moved back into place but does nothing. I think #16 is probably broken beyond repair, but I'm not sure. Any suggestions?

I just spent time typing out basically an exact copy of what Tician said, he's on the money.

Please contact us for any additional support you need to get your robot back up and running, you can find our contact info on our store homepage!

Harper
06-09-2015, 09:53 AM
Thank you tician and Tyberius for the answers.

Our problems were completely solved by following your instructions. 1 and 8 went back to normal after we assigned them the correct IDs. A small part of 16's internal structure that holds the gears broke, so we were able to replace it and it worked fine. 11 was the only one that we were not able to fix, but we got a replacement.

Thank you again.