Challenger ArcMate question

  • Hi!

    I work with an ArcMate and big sized work pieces. There is hundreds of weld beads and high tolerance assembly, so I need to expend a lot of time in sense touch and movements. I tried to omit some searches, but just don´t work and will not.

    Long story short, there is some way I can change the programming lines from "SEARCH SEARCH SEARCH WELD WELD WELD" to "SEARCH WELD SEARCH WELD SEARCH WELD"? How can I deacrease significantly the movement time? How can I control the wire lenght before and after welding? Can I install a wire cutter in the robot arm? Can I control the burnback finely? Can I use the work piece to "burn out" the wire so I can control the wire lenght during movements?

    (Laser and Vision options are not perfect because of high tolerance assembly and high cost, TAST don´t work because there is a lot of small weld beads)

    Any help is welcome!
    Thank you!


    Sure, why not? That is actually what I would recommend, as the workpiece might deform slightly while being welded, making the initial search results useless...


    How can I deacrease significantly the movement time?

    use as many JOINT motions with high speed and CNT value, optimize trajectories, manage joint limits and take them under consideration while moving between seams, adjust welding parameters to increase welding speed.


    How can I control the wire lenght before and after welding?

    Wire cutter + a push-pull torch to avoid the wire being pulled back /pushed out while the robot moves


    Can I install a wire cutter in the robot arm?

    Never heard of anything like that, would be problematic. Better to use a cleaning station near the workpiece and the robot


    Can I control the burnback finely?

    Depends on the power source and interface used.


    Can I use the work piece to "burn out" the wire so I can control the wire lenght during movements?

    Not really sure what you mean here.

    Generally, to avoid problems with wire length, you can use a sensor installed on the torch, or just use the gas nozzle for touch sensing (a cable to supply touch-sensing voltage from the power source is required in this case).

    I've done some interfaces between Touch-Sensing and analog laser distance sensors - all you need is some KAREL code. But to make it simple, you could just use a 2-state switch - either a mechanical limit switch (however, I'm not sure if this will provide enough accuracy and repeatability) or optical (maybe a programmable laser sensor?).

  • You´ve been posting many questions about touch sensing ....

    Touch sensing without wire cutting is helpless ...... Definitely you MUST install a wire cutter on the robot to get a constant wire length for touching
    Also, your Welding torch should have wire brake

    According to the manual you do the "search" with a laser sensor, the interface is part of the touch sensing package, you only need to install it and define the I/O
    Basically, instead of moving to touch the part the robots just fires the laser and the distance is read to compute the offsets

    I´ve never use it ..... search with wire touch was enough

    I used to Weld large pieces also and the strategy was to make all touch sensing then the Welding
    Welding after each individual search was not an option because you need to cut the wire prior to search

    Doing all the search requires cutting the wire once

    Your application is multi-pass???

    If you have hundreds of welds the laser option might be cost effective because it would reduce the cycle time
    But you probably need simulation to validate the position of the laser.

    What do you mean by "small Weld beads" ??? Which size is your shortest bead??

    Edited once, last by robotero ().

  • I do have a wire cutter, but as you said, I can't use it after every weld.
    There is no multi-pass.
    It have hundreds of beads with 50mm to 150mm.
    Until now, I think 10 searches and 10 weld it is the right number. So I can avoid distortions and I need to clean the torch after 10 welds anyway...

  • Quote


    That analog sensor version was a custom-made thing that I programmed, actually sold as an option by my previous employer. You would need a Profinet or EthernetIP interface to implement it, as the sensors that we used supported these protocols. Try contacting Weldstone Advanced Automation if you are interested in the product.
    What the software does is interpretation of the sensor input (32-bit) to detect a rising/falling edge of the workpiece and sending the result to the Fanuc's own Touch-Sensing interface with forced IO setup. The whole package is configurable via TP-screen menu and can be freely activated/deactivated to switch between the laser sensor and wire search.
    If you'd like to program something like this yourself, you'll need some KAREL experience and a bit of tinkering with system variables responsible for Touch-Sensing.

    The 2-state laser sensor can be used with the standard FANUC Touch-Sensing interface in the newest software versions: go to Menu - Setup - Touch Sensing IO - there, you can select the type of TS: either Wire or Laser Sensor.

    Edited once, last by bidzej ().

  • I am wondering if anyone out there has any experience with welding expanded metal on a fanuc robot ? i am currently running a Fanuc ARC Mate 120iC with R-30iB Plus, as of now we are using an analog laser search. my issue is with the expanded metal changing, my search points often end up coming in contact with the part before the search. is there a possible way to tell the robot after this happens to move a set distance and attempt the search again? i have attempted an if statement but as soon as that sub program runs it returns to the search point and comes into contact again. any help with this would be greatly appreciated.

  • To Zsalonek,

    We tried, but the expanded metal bonds would not be in the same places on each piece. We switched to wire mesh, the wires were more consistent with this material.

    The welding was mostly in straight lines x and y, and this also sped up the cycle times by almost half.

    Don't know if this will work for you application or if it is even an option, but it worked for us.

  • Wire mesh, you can google it. Comes in different size wire diameters, and different size square openings.

    If you find the right source, they can make panels to whatever size you want.

    Picture A piece of window screen, with thicker wire, and bigger openings.

    The size we use is .100" diam wire, with 2" square openings.

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