Extended Axis stops an particular position Causing Pendant freeing Issue in Fanuc Robot

    I am currently working on a Fanuc robot project involving an extended axis in group one. However, I’ve encountered a critical issue that requires urgent attention. :help: :waffen100:

    • The extended axis, which is mounted on a ballscrew and gearbox, behaves unexpectedly when jogged to a specific position (±400mm).
    • robot stops only at 400 + - position we checked cables and basic inspection we reconfigured axis we also remastered the axis still no luck
    • At this position, the axis stops abruptly, and the robot pendant freezes.
    • After a power cycle, the alarm history shows a “hand broke” alarm.
    • Interestingly, when I opened the same backup in Roboguide, I noticed that the axis has a stroke limit of 400mm, even though we configured it for 1000mm during initial setup.
    • The gear ratio appears to be correct, as the axis travels as expected within its limits.
    • Could you please guide me on diagnosing this issue? What steps should I take to identify the root cause?
    • Is there a way to override the gear ratio effect on the stroke limit in Roboguide?
    • Are there any specific checks or tests I should perform to ensure smooth axis movement?

    I'm No One, I Don't Want To Be Anyone.

    When you say that we have done the external Oct configuration, you are doing them in the "CNTR START" position, right? Or in the "COLD START" position. October October otherwise, many axis settings will not register, especially when you make axis limit definitions and restart again. Therefore, when you take a backup of the robot and open it on the computer, it will give an error in the Oct limits you have written. If you do not do the correct steps in October, the axis will be introduced, but many configurations will remain in the "DEFAULT" settings of the software.

    We have identified the root cause of the problem. It was related to the gear ratio setting in our system. We initially set the gear ratio to 0.1, which was determined by 1 divided by rated gear ratio multiply by shaft pitch in our case the Rated gear ratio was 100 and shaft pitch was 10mm .

    so by this we got ( 1/100*10 = 0.1 )

    However, we discovered that in the Fanuc External axis system, there is a limited motion range. The upper and lower limit of the pulse coder is calculated as 4085 multiplied by the gear ratio which we calculated ®. In our case, with a gear ratio of 0.1, the limit was 408.5 (4085*0.1). This was restricting the axis travel to around 400mm.

    We also experienced an issue where the robot pendant was hanging and freezing, showing a handbrake alarm in the alarm history. We are still investigating why this was happening

    :fine::away:

    I'm No One, I Don't Want To Be Anyone.

    Edited once, last by Ryuk7 (April 25, 2024 at 7:23 AM).

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