UTool and UFrame after Re-Master

  • Hi,


    Do I have to touch up the u-tool and the u-frames after having the encoder batteries die. We re-mastered everything on our 4 axis m1-ia for a pick and place application but we aren't getting repeatable placement on the conveyer.


    Other than those frames is there anything else that should be done after a re-master?

  • Place your Ad here!
  • Not repeatable after remaster? Might want to remaster again. Points are not likely going to be exactly where they were, but I think it should be repeatable.


    I would say remaster until things are repeatable and then touch up points and/or frames. But you might wait until someone more confident than myself chimes in...

  • Are the frames taught or directly entered?

    By repeatable do you mean that each cycle the robot position changes or that the placement position seems off after the recent remaster?


    How did you master the robot? Zero mastering? quick master?

    I bet you just mean that your positions are a bit off compared to before the mastering. Unfortunately we cannot exactly hit the Zero marks with the eye. Every re-mastering using the vernier signs will produce slightly different programs.

    Put your robot to Zero position and verify that all Vernier marks are aligned in every axis and then reteach your User and Tool frames. This is about as close as you can get to your old configuration when using Zero mastering.


    If by not repeatable you mean that each cycle the same position is shifted then this is a different story that suggests a mechanical problem on the robot or complex logic used inside the program that is not accounted for. (a change in a PR, a calculated PR, a wrong offset application etc etc)

  • Famous_Fella The pick and placement position is off after the remaster. We did a Zero Master. But since we did the remaster we have to reteach the user and tool frames because those values are entered directly, they aren't taught positions.

  • Famous_Fella The pick and placement position is off after the remaster. We did a Zero Master. But since we did the remaster we have to reteach the user and tool frames because those values are entered directly, they aren't taught positions.

    Yes I guessed so. For the sake of it, verify mastering by putting robot on zero. Also keep in mind it is not a good idea to use Direct entry for User Frames. User Frames should always be taught imo.

    There is also another trick you can do that is a high-risk high-reward move and it can produce great results but it is a bit more advanced. Using the same tool frame as before and without teaching it, I would try to hit the zero (reference) position of the frame. If the directly entered frame points to a solid reference position in space (a pin, an edge point etc), move to that position and then correct the JOINT positions of each axis separately until the robot is correctly aligned with the frame reference point. Write down the difference. Lets say you had to correct +1.3 degrees on J1, -0.7 on J2 and +1.3 on J4 in order to hit the reference position of your frame. Put your robot to zero. Apply the corrections to the specified axes and re-master them to zero.

  • Yes I guessed so. For the sake of it, verify mastering by putting robot on zero. Also keep in mind it is not a good idea to use Direct entry for User Frames. User Frames should always be taught imo.

    I will try that, these are systems we got from a integrator back in 2014 we are trying to being them back into production after being shut down for about 3 years. So they used the direct entry, I can attempt to create a new user frame that is taught.

  • Yes I guessed so. For the sake of it, verify mastering by putting robot on zero. Also keep in mind it is not a good idea to use Direct entry for User Frames. User Frames should always be taught imo.

    There is also another trick you can do that is a high-risk high-reward move and it can produce great results but it is a bit more advanced. Using the same tool frame as before and without teaching it, I would try to hit the zero (reference) position of the frame. If the directly entered frame points to a solid reference position in space (a pin, an edge point etc), move to that position and then correct the JOINT positions of each axis separately until the robot is correctly aligned with the frame reference point. Write down the difference. Lets say you had to correct +1.3 degrees on J1, -0.7 on J2 and +1.3 on J4 in order to hit the reference position of your frame. Put your robot to zero. Apply the corrections to the specified axes and re-master them to zero.

    What you are saying is to jog the robot to the coordinates of the tool frame or the user frame? IF the coordinates relate to a position in space IE a pin. Than switch to joint mode and jog the robot to the tip of the 'point'. Than take the values from the joint cord system and calculate the differences than jog the robot to the Vernier marks and re-master. But where would I input the differences that I calculated. I'm gonna send you a PM maybe you could call me to explain in detail if you wouldn't mind :smiling_face:

  • What you are saying is to jog the robot to the coordinates of the tool frame or the user frame? IF the coordinates relate to a position in space IE a pin. Than switch to joint mode and jog the robot to the tip of the 'point'. Than take the values from the joint cord system and calculate the differences than jog the robot to the Vernier marks and re-master. But where would I input the differences that I calculated. I'm gonna send you a PM maybe you could call me to explain in detail if you wouldn't mind :smiling_face:

    Go to your frame screen, Enter the frame you want and write down the Direct Entry coordinates. Now create a program and inside declare a point anywhere, doesn't matter but ake sure you use the correct UTOOL and User Frame 0 (UF0), and change its coords to the frame coords. Move there. The robot should now be close to an identifiable reference point. A point someone (the integrator or a programmer in the past) used as the frame reference point.


    Open the point's position data and change the representation to joint. You should now see the joint angles of each axis for this position. Write them down.


    Now switch your jog mode to JOINT and try to correct the position of each axis separately so that the robot tool is aligned and touching the reference point. You should be carefull as to not correct one axis too much but better spread the fault difference by applying small corrections to every axis.


    Now when you are done and you have aligned the robot with the frame reference point, declare another point in your program. You should now have 2 points: point 1 is the original point from the Frame Coords used as direct entry and point 2 is the modified version of it in order to touch the reference point.


    Write down the JOINT angles of each axis for point 2 and calculate the difference. You should come up with a result of minor degree difference for some axes or all of them negative or positive, the difference margin should not be large. If it is large something has gone wrong.

    Now, put your robot axis to ZERO position and using the results from your previous calculation apply them to each axis. Again, you should check to see that after applying the correction to each axis the marks are not way off of where they were supposed to be, it should be +-2 max 3 degrees. If the Vernier mark is visually way off then something has gone wrong. When you are done applying the corrections, master your robot with zero mastering, Calibrate and you are done!

    Repeat the procedure by moving to point 1 (the frame ZERO point, not the corrected one) and verify that the robot now correctly aligns with the frame reference point by using the direct entry values.

    Things that can go wrong:
    Identifying and using a reference point that is not a good reference point. (worn out, or with excess tolerance due to wear and tear or age).
    The frame may (and most propably) has been set when the system was brand new and before any tolerances to the system's parts were introduced due to normal aging and wear. The same goes for the mechanical parts of the robot. Machines age, and as they age new tolerances are introduced and we copensate our programs to correct any faults due to aging.

    If you come by any of these possibilities, remaster to zero as before using the marks and your eyes and just reteach the user frame. The tool frame does not need to be taught, you can use the direct entry values.

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

Advertising from our partners