IRB2400/16 Joint falling after Deadman release

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Dear community,

I have a problem while jogging the robot. The Joint3 of the robot is falling after releasing the Deadman switch of the Flex Pendant (i.e., moving with the middle position of the Deadman an then terminating the jog releasing the switch). 
It seems that happens only on the joint 3 and only during jogging.
No errors appear on the Flex Pendant, the falling motion is in the order of magnitude of 4-5 centimeters.
I haven't changed the payload and the programs or settings by weeks and the robot was off of at most 3 weeks.

What it could be? Can I solve/do something?

Federico 
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  • lemster68
    lemster68 ✭✭✭
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    The brake is slipping.  If it is not motors on push that axis to get a feel for what force it takes to overpower the brake.  Hopefully, you have another good robot which you can try the same thing to verify that the brake is slipping by the difference it takes to move them.
    Lee Justice
  • Kappa95
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    Unfortunately I don't have another ABB robot to use as comparison. For the push test Can I stay in manual mode or is it better to stay in Automatic with motor off? Also I should expect some error or only the joint moves and then stops?

    Thank you
  • lemster68
    lemster68 ✭✭✭
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    Motors off is the same whether it is in teach or auto.  You could get an error like joint speed too high, but I would not expect that anything will go majorly wrong as long as the power is on.  If you move it with power off you will lose rev counters.  For safety's sake let's just say you do so in teach.
    Lee Justice
  • lemster68
    lemster68 ✭✭✭
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    Also, don't put yourself in a position in which if it fails completely, it will fall on you.  Don't get underneath the robot.
    Lee Justice
  • Kappa95
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    lemster68 said:
    Motors off is the same whether it is in teach or auto.  You could get an error like joint speed too high, but I would not expect that anything will go majorly wrong as long as the power is on.  If you move it with power off you will lose rev counters.  For safety's sake let's just say you do so in teach.
    Perfect! I will do the test tomorrow. Then if it slips I imagine that I should contact ABB for repairing. 
    Thank you
  • Kappa95
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    I did the test pushing the robot and effectively the robot moves and then stop with minima force. I run also the BrakeCheck routine and it shows the brake problem.

    Thank you
  • lemster68
    lemster68 ✭✭✭
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    I didn't even think about the brake check.  Good job.
    Lee Justice