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  1. #1
    Join Date
    Jun 2006
    Posts
    4

    camsoft G1,G2,G3,

    I looking for help in the ratio setting area , I have it set to 10160 encoder counts = 1 in. if I program a G01 X30 F5 the table moves 30 in. I have Versa gage mounted and alinged to the table and the readerhead attached to the spindle I am removing the backlash before the G01 X30 F5 move this appears to me that the ratio setting is correct ?
    Futher more if I program a square like this
    G00 X0 Y0
    G01 X5.555 F100
    Y5.555
    X0
    Y0
    this returns to my zero this works fine even if I repeat the G01 X Y moves many
    times say 50 times it works . But if I do a G2 or G3 on the first time around it will be off by .0003 on the X and Y readouts and the more times I run it the futher off it gets until it gets beyond the tolerance setting then it errors out. Has anyone had a similar problem is the ratio setting the solution or is it something else ?
    I have cnc plus V5.8 and Galil Card DMC-2162 ethernet

  2. #2
    Join Date
    Mar 2004
    Posts
    1542
    I'm not much help, but you have your ratio is set correctly.

    Just curious, does the problem occur with all fanuc arc types? Pure guess here, but absolute I J parameters (fanuc arc=1) might not build up error with repetition.

    I did a search for solutions on tolerance, there's a lot of reading here on how to set up system tolerance, position error etc.

    Karl

  3. #3
    Join Date
    Mar 2003
    Posts
    4826
    Try running a test with the backlash set to zero, to see if that might be the source of the cumulative error.

    How large were the circles that you were running? Is there any difference in magnitude of error between a 1" radius and a 10" radius movement?

    Does your backlash adjustment work out exactly in whole encoder steps? I presume your encoder is running in quadrature resolution. How many lines/rev is your encoder?
    First you get good, then you get fast. Then grouchiness sets in.

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

  4. #4
    Join Date
    Jun 2004
    Posts
    16
    Last year we where cutting about 500 speaker holes a day. Circle after circle and it worked great on that job.

    Long before that there was another situation were I had a small .0005 error but only in some parts. It made me think it was in those programs. It wasn't. There was a bad spot in the lead screw and only some programs would run through that part of the table. The encoder counted incorrectly there. Ran the same part in demo mode and the error didn't show up. I used their adjust file to correct it. So far its been years now working as accurate as ever. I recommend Camsoft to every one I meet.

    Run your same part in demo mode. If the error still shows up look in the program. If it only shows in real mode you may need to use the adjust file to.

    Johnny

  5. #5
    Join Date
    Jun 2006
    Posts
    4

    more info on G2 G3

    The encoders are mounted to the motors they are 1000 count per rev the motion board quads this input to 4000 counts per rev
    I havent even tried to use the backlash comp yet it is set to 0 in setup
    My program is
    G90
    G70
    G01 X0 Y0 F10
    G02 I-2.555 J0 -----at this point X readout .0006 Y readout .0006
    G02 I-2.555 J0
    G02 I-2.555 J0
    G02 I-2.555 J0
    G02 I-2.555 J0-----at this point x .003 y.0035
    M30
    after last move I should be at x0 y0 with in reason , even if I program a G00 or G01 X0 Y0 after the circle the accumulated error still remains , it's like the motion board thinks it's at the position but the readout indicates it is someware else also the table matches the readout position
    it dosen't matter what the circle radius is I still get the error and it tends to accumulate each pass I have tested radius values of .5 to 5 in. I have tried this in each G2 and G3 same results

  6. #6
    Join Date
    Mar 2003
    Posts
    332
    I know you wrote the software multiplies the count from 1000 to 4000 per rev. So the encoders are set up for quadrature, not pulse in the setup.exe? I had an accumulative error when I set quadrature encoders as pulse on my system. Much more sensitive to noise.

    What does .0006 equal as encoder tics? More than one, less than one? Is this an accumulative math error or a reading error?

    All couplers tight? No shafts slipping?

    Happen at all speeds, fast and slow?

    G02 and G03, or just one direction?

    When you say the "readout" is .0006, is that the number on the screen when it should be .0000, or is that a physical measurement on the machine?

  7. #7
    Join Date
    Jun 2006
    Posts
    4
    I have 10160 counts per inch so .0006 is about 6 encoder counts , every thing is tight , it happens at any feed rate , in both G2 and G3 , I start the circle at x0 y0 and end at xo yo but the axis display showes the error the table is were the axis display show it to be but the program is sending it back to xo yo the error accumulates each time arround the circle , if I use the diagnostics it showes no position error but the control will see it as being out of tolerance and shun down , which it is really out of position . I have tried both fanuc arc types still a problem

  8. #8
    Join Date
    Dec 2003
    Posts
    24216
    This seems like a prime example where the diagnosis can be performed by programming the card with Galil s/w using native commands.
    There are some examples in the Galil manuals for doing interpolated circular moves.
    If the Camsoft screen display shows where the control thinks it is, instead of where it actually is (most CNC machines have this characteristic, even Fanuc), then one way is to use a Galil TE, which will indicate exactly how many encoder counts of error actually exist.
    If this is performed at the end of a move, this indicates directly the error.
    If either a linear or interpolated move shows a large encoder error when in position, this usually smacks of tuning.
    Most Galil systems I have installed, I have achieved one to zero encoder error.
    Al.
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

  9. #9
    Join Date
    Jun 2006
    Posts
    4
    I recently got a local dealer to let me install his pro version to test if software related , so I set all parameters like I had in the plus software and the problem went away , leads one to think it is a internal software problem

  10. #10
    Join Date
    Apr 2003
    Posts
    332
    Daryl,

    The problem isn't what it seems. There is some one else writing you back right now. You're under the wrong impression and CNC Professional works in the exact same manner. You'll see this shortly when they get done writing you back and hopefully you'll be a gentleman and post your results here.

    Tech Support
    CamSoft Corp.
    (951) 674-8100
    [email protected]
    www.cnccontrols.com
    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

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