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  1. #1
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    Jan 2016
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    5

    Problem with circular shapes

    Hello everyone,

    I'm having trouble producing circular shapes (no issue with linear shapes), but I have not been able to find the source of the problem. When the figures are small, circles end up looking like ovals somewhat flat along the x axis.



    I tried to tune the X and Y displacement of my motors, as well as speed and acceleration. I think the X and Y displacements are fine, and any error should be below 0.07% according to my calculations. With respect to motor speed and acceleration, I hear the change, but I have not been able to see noticeable improvement. I thought I had, but in a later try I was not able to reproduce my results.

    My setup has two planetary gearboxes 10:1 in the X axis (one on each side) and no gearbox for the Y axis. Ball bearings and gearboxes are brand new. I think the motors have been working for about 10 years now.

    I have not checked for backlash yet, but the machine was allegedly working fine until a few months ago. I don't know if this is something that can change over time.

    We control our machine using Mach3.

    What can I do? Please advise.

    Thanks.

    Mario

  2. #2
    Registered
    Join Date
    Jan 2011
    Posts
    186

    Re: Problem with circular shapes

    that's what backlash does -
    www.signtorch.com

  3. #3
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    Sep 2008
    Posts
    68

    Re: Problem with circular shapes

    How old are your ball screws? How well are they and the drive nuts protected from Garnet?

    I've seen similar misshapen cut results when the ball screw or nut are very worn- in our case garent found it's way onto the screw and over time it ate the drive nut from the inside out.

    The other thing to check is the gearing on X= could be that you aren't perfectly in synch on both sides of the bed causing drag and crabbing.

  4. #4
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    Join Date
    Jan 2016
    Posts
    5

    Re: Problem with circular shapes

    They were 10 years old. We have new ones now and the problem was fixed. Thanks a lot.

  5. #5
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    Join Date
    Sep 2011
    Posts
    9

    Re: Problem with circular shapes

    You can change cw distance settings

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