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OX cnc: strange happenings with the A-axis

Discussion in 'CNC Mills/Routers' started by nicom1234, Jan 30, 2017.

  1. nicom1234

    nicom1234 Well-Known
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    Have finally set up the ox cnc after having some problems with the first cnc xpro v2 board I bought (would not flash, so it was bricked I think)..I have ran into some problems with the second xpro v2 board and was wondering if anyone has had similar problems...

    The a-axis is currently set to act as the second 'y-axis' stepper as normal on the cnc xpro v2 board, however, when I jog the y-axis (which moves fine), the mirrored a-axis eventually kicks in and starts moving a few seconds later, like it is delayed somehow.

    Has anyone seen this before? Any help would be very much appreciated!
     
  2. David the swarfer

    David the swarfer OpenBuilds Team
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    check the current setting on the drivers, they must both be the same.
    check the microstepping settings on both drivers, they must be the same.
    disconnect the belts and check that both motors run properly without load.

    there can be no 'delay' since when you place those jumpers is connects the Y and A drivers STEP and DIR pins together. There is no software involvement, therefore can be no delay. But if one motor is turning slower than the other (wron microstep setting) then the gantry will twist until there is enough force to drag it along with the faster one.
     
  3. nicom1234

    nicom1234 Well-Known
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    Thanks for the help and suggestions David. That does clear up if it was software based or not. Have checked the steppers without the belts and it has the same problem. Will have a look at the settings in the universal gcode sender to see if they match.
     
  4. nicom1234

    nicom1234 Well-Known
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    Unfortunately after changing each line of the GRBL settings, the problem was still not fixed. It is also actually the Y-Axis that is not working and the A-axis that does not work. Have emailed the guys at spark-concepts to see if they've seen this problem before (they have delivered great customer service last time I had a bricking problem!)
     
  5. David the swarfer

    David the swarfer OpenBuilds Team
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    If you run one motor at a time (on the same driver), what happens?
    Does the gantry move the same distance on both motors?
    I ask because I just had the idea that the 1 motor may be 200 steps/rev and the other 400 steps/rev.
     
  6. nicom1234

    nicom1234 Well-Known
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    When I tested the motor without the belt - it turns out I was testing the wrong one (difficult when theres a load of wires!) Have now tested the correct one without a belt and it is not turning at all.
     
  7. David the swarfer

    David the swarfer OpenBuilds Team
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    time for a new motor?
    test that motor on both drivers, if it does not run at all, then get a new motor.
    if it runs on one of the drivers, time for a new driver.
     
  8. nicom1234

    nicom1234 Well-Known
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    Tested the motor on other drivers and it works, which is a shame because that would have been a nice easy fix. Speaking to Spark-concepts, it looks like im shipping the board back to them to look at and im sure they will be able to sort it.
    Thanks for all the help David!
     
    David the swarfer likes this.

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