Axis Limit (J4) on an LR Mate 200ic 5L

    Robots are inverted on the ceiling of the machine. I am looking to rotate the 4th axis 180 degrees to eliminate an external umbilical and relieve running wear and movement issues. The current soft limits are set to -190 to 190. I only need a possible 25 more degrees. I can open it up to a -370 and there is little impact on the wires and have not found a hard stop as of yet. Has anyone stretched the limits as of yet. Need to avoid the electrical connection and the EOAT.

    The motion paths are set and currently use little of the 4th axis. The umbilical is the main problem cause. Due to the winding up of a spring it pulls against the robot creating small part placement issues. We need to be accurate to .2mm. The theory is how can you write neatly while I am bumping your arm (Proven by a machine test). By rotating the axis 180 degrees it allows access to the robots air fittings and electrical plug, if the robot were not upside down it would not be an issue. After all if they didn't want them changed why would you make it a soft limit?

    If there is little use of axis 4 and you want to rotate 180 degrees and the current axis limits are set to +- 190 then you have what you need to accomplish this.
    You need to change the programming.
    Step through the program and at point where you want to change axis 4, make the change you want, change the motion to Joint and record it.
    It sounds like the positions are taught in Linear and the robot is deciding how to get to the position.
    In Joint you have more control of the robot.
    Like I said you need to change the motion of the program.

    Quote from dmbj


    to answer the original question....

    yes you can go -275 to +95 on J4 and you will be fine.

    So there are no mechanical/physical limitations on J4? So the set limits are arbitrary and can be set to whatever you want, just keeping the 370 degrees difference between them? Can this be taken to an extreme of say +0/-370?

    I got your point: the I/O connector and pneumatic ports are on the top of the robot.
    Robot is ceiling mounted so the ports are facing down an is better to get them facing upwards ....
    Robot is already programmed .......with ports downwards

    Double check if you can open the axis range of motion without affecting the internal wiring and tubing
    Study the mechanical drawings or ask fanuc directly

    Now, to modify the paths: you only need to change the posture configuration (You don´t need to re-teach everything)

    Your positions are now in Flip posture (positive angles of J5) so, change to No-flip (use negative angles of J5)
    The effect would cause the controller to rotate J4 180 degrees and J6 rotates 180 in the opposite direction to compensate.

    You can also change from elbow UP to elbow Down solutions

    Probably that would also help in your application

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