One of TWO robots failing movement with crunch noise

[J_Parker]

uArm Serial No.: (the No. at the bottom of each uArm reading “UARM-XXXXXXXXXX”)

Firmware Version: 4.0

Operation System: Win7

uArm Controlling Method: C++ app

I have TWO robots. Both are controlled with two copies of the identical program running on windows pc.

In the first video (robot_good.mov https://drive.google.com/file/d/1N8TFW3BmhFU2O-PCxR2nvCSjYPYda0G_/view?usp=sharing )

You can see the robot starts in front, moves up…the camera takes a picture, then it moves up again and over to the right (robot’s left) and lowers.

This movement has been done thousands of times by both robots.
Both robots are calibrated the same as well.

In the second video (robot_fail.mov https://drive.google.com/file/d/11jNhwDXiMv-sMv5XhDlXxQI0aagcduf0/view?usp=sharing )

It is the problematic robot (the camera is not attached), but the controlling program and movements are the same. Yet when it moves to the robot’s left to lower, you get the “crunching” noise of the motors….and from then on the robot arm is out of place.

WHY is this happening on the second robot and not the first? And it only just started happening. I recalibrated both robots multiple times and they seem to have the right coordinate systems that are identical….can you help explain?

[J_Parker]

I want to also add that on the robot that is good every so often it moves to a location and while there are no obstructions, the robot fails to get ot the right location and again the motors crunch. I am concerned that perhaps i have worn out the cables connecting the motor encoders to the control board. I have used both robots extensively to sort about 10,000 cards and perhaps the mechanical stress on the cables has caused them to have some intermittent connection problems.

I say this because the failure mode seems to be only in a particular location does the robot start to fail. Meaning, when the robot attempts a particular destination…then it fails…occasionally, not predictably. but over time this occurs more often.

i have submitted a support ticket with no response.

• jim

[jane]

Hello James,
Please check your email.
Thanks for your understanding.

[J_Parker]

hi jane. still no response via email from your support team.

[jane]

Hello James,
please check your email, If you have any problem, please send it to my email: shiyanfei@ufactory.cc

[J_Parker]

Hi Jane. I was able to repair one of my robots (the one that only had intermittent problems). It was the thin cable going from the motor to the control board. I did have one spare that was good. I also notice the connector on the motor is not very good, the cable can wiggle and lose connection very easily. I think i was able to put the right strain relief on the cable to keep it in place. time will tell.

I am guessing the other robot i have also has a bad cable (or two). Can i get some extra cables sent to me? thx, jim

[jane]

Hello James,
Please send the picture of the cables that you want to replace to me, and please provide the SN of the bottom of the uarm to me.
In order to be able to respond to you faster, please send the above information to my email: shiyanfei@ufactory.cc