Fanuc Wall/Rail Mount Issue (Collision Guard/Detect)

    I have a M20iD/35 mounted on a Rail (wall mount) 100ft long. There is little space between the rail and the working zone, so I have to extend the arm along the Y-Axis to reach down into the working cell. However, when I get close to this extended position (see image Robot_Position_Error_Status), I start getting "Servo-050 Collision Detect Alarm (G:1 A:1)", and the robot stops abruptly. I've tried turning off "Collision Guard Status" off, but doesn't seem to make a difference. The only way I can continue to move is to constantly press the RESET while holding down SHIFT.

    I know it can be turned off in a TP program, but that doesn't help me when jogging to teach in points.

    This seems to be an oversight on Fanuc's part because on a wall mount configuration, J1 constantly experiences a high load due to the gravity affect on all the axes (see image Torque_Reading), whereas on a traditional floor mount, J1 would only experience high load from inertia. In the working zone (see photo Robot_Position_Working), I don't get these errors because the arm is close to the 6 o'clock position (relative to wall mount).


    Does anyone know how to permanently disable the Collision Guard feature, or what I can do to get around this issue?


    https://drive.google.com/file/…Q_idwsnr/view?usp=sharing (Collision_Guard_Status)

    https://drive.google.com/file/…xsTlZyyB/view?usp=sharing (Robot_Position_Error_Status)

    https://drive.google.com/file/…lfPxAKaF/view?usp=sharing (Torque_Reading)

    https://drive.google.com/file/…MaieFTuE/view?usp=sharing (Robot_Position_Working)

    • AD

    Fanuc does have an operational limit defined for when the robot is mounted at 90 degrees. You might be running around in that area, judging by the pictures.


    Edit: wrong diagram. See my post below.

    Check out the Fanuc position converter I wrote here!

    I had the wrong diagram. Range is even more limited for the M20iD/35M. I think you are running in the "no go" area.


    I think your only solution is a mechanical change. It you need that reach, you may need to add in an angle plate to get that area of the envelope back.


    Check out the Fanuc position converter I wrote here!

    Quote from Nation

    I had the wrong diagram. Range is even more limited for the M20iD/35M. I think you are running in the "no go" area.


    I think your only solution is a mechanical change. It you need that reach, you may need to add in an angle plate to get that area of the envelope back.


    Thanks for your input, and not really what I wanted to hear. 8|

    You obviously have more knowledge on this topic than I, but for obvious reasons, I have to explore all my options. What I find puzzling is the fact that I can jog the robot in this position if I SHIFT/RESET and confirm overriding Collision Detect with no issues. The other thing is that setting Collision Detect to 1% makes no difference from 100% or 200%. I have to rule out anything else may be wrong in my configuration.


    By "add in an angle plate", are you saying I need to turn the base of the robot 90 degrees so that X is along the rail direction? Or mount it upside down (ceiling mount)? This is a very large structure, so any changes mechanically would be a huge undertaking.

    I'm not sure about your application, but I think the easiest would be to add in a 45 degree spacer/weldment in between the carriage and the robot base. That would rotate the robot about the Y axis. Plus or minus, it wouldn't matter. That would get the robot back into the "clear" (non-shaded) zone, allowing you to use the full range of motion.


    The only other option is to try and stay out of the "no-go" area.


    You might be able to get through there if you run the robot at teach speeds in auto, with low ACC modifiers attached to every point. Probably not in the cards for cycle time reasons.

    Check out the Fanuc position converter I wrote here!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account
Sign up for a new account in our community. It's easy!
Register a new account
Sign in
Already have an account? Sign in here.
Sign in Now