Make tool frame same as world frame

    Hello,

    We have an LR Mate 200iD with a R-20iB controller. I was trying to create a tool frame where the center point would be set with direct entry. The problem is when setting the point, we know the point's data how it would be relative to the world frame.

    The tool frame isn't parallel to the world frame. When jogging the robot in +X, +Y, the tool frame is at an angle to the world frame. Is there a way to force it to be the same as the world frame? I tried direct entry with an angle offset, but it's giving me unpredictable results when I rotate about a point off axis.

    Thank you.

  • Go to Best Answer

    I think you should be using a Userframe for for what you are talking about. The tool frames are for EOAT and as such will rotate their x,y planes with rotation of the robot's 6th axis. Userframes however will always be orientated in the same. An uninitialized userframe will match up to world frame exactly.

    Quote from I3ooI3oo

    I think you should be using a Userframe for for what you are talking about. The tool frames are for EOAT and as such will rotate their x,y planes with rotation of the robot's 6th axis. Userframes however will always be orientated in the same. An uninitialized userframe will match up to world frame exactly.

    I tried this, I changed the Y of a user frame to be 200. When I switched to the uframe and jogged the robot in J6, it still rotated it the tool around its center.

    I also tried it in a program.
    PR[1,2] = 200

    UFRAME[1] = PR[1]
    UFRAME_NUM = 1

    PR[2,6] = PR[2,6]+90
    L PR[2]

    It still rotates about the original center of the tool.

    I read up thanks. Seems like a tool frame is the way to go for what I want to achieve. The only problem is, when rotating about an off axis point, the robot drifts by one centimeter in the X direction. I used direct entry and just tried using the default 0 tcp with a change in Y.

    I’ve seen posts about mastering causing drift issues, and I’ve done a quick master with the witness marks a month or two ago.

    When rotating J6 in world, W and P do change by 1. Would that cause the drift?

    The thing is, I need to change the axis of rotation depending on the workpiece it picks up. We know the measurements of the workpiece, and where the center of rotation should be offset from the center of the faceplate. I don’t have a pointer tool unfortunately, but I tried the 6 point method with a mark at the end of our tool

    The tool is just an extension in the Z axis from the faceplate. The center is still lined up with the center of the faceplate.

    Edited once, last by jsd5 (March 6, 2021 at 4:57 PM).

    • Best Answer

    So if I understand correctly, you want to rotate around the tool Z axis, but have that axis offset from the center of the faceplate.

    It should be as simple as setting an X or Y value for the tool frame. If it drifts in x or Y while rotating only the R angle then you must use trial and error to adjust the tool frame until it is correct.

    The only way to determine if it is a mastering issue is to mount a solid, sharp pointer, teach a 3 point method, and see if you can rotate on point.

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