1. #1
    To cut a long story short; I've revived my CNC mill, from being sat on my bench doing nothing for around 9 months because of a damaged spindle.
    I got a new spindle custom made for the machine, just fitted it tonight; switched on, booted up, and put the thing into first gear...

    However: The X-axis sounded VERY ODD.
    Took a closer look, and it is missing steps BADLY + stalling very often.

    If I jog X+ and it starts to stall, giving it a little nudge tweak on the ballscrew brings it back into movement.
    It does stall/jitter in both directions, but more so in one that the other.
    Turning the ballscrew by hand doesn't mechanically feel that sticky; which is what has confused me.

    I removed all the bellows, gave it a good clean (not that it needed much) and oiled all the ways and ballscrews. Ran it back and too, to let it soak in. And still the same.

    If I send single steps, then it just jitters back and to on either step.

    At the highest feed rates (1320mm/min) it doesn't seem to have this problem. Just anything less than this causes the issues...

    SO: Is this a "bad stepper" one on it's arse? Or a mechanical issue?
    It would be a *MASSIVE* pain in the arse to fully remove the X-axis and investigate in detail, so I'm not jumping to that immediately.

    Anyone any ideas?

  2. #2
    You could try swapping your drivers around at least that would rule out those, also have you checked the software has had no changes again send the x signals to another axis to rule this out, im no expert but trial and error usually lights some lights

    Always bear in mind that your own resolution to succeed is more important than any other - Abe Lincoln

  3. #3
    i2i's Avatar
    Lives in Cardiff, United Kingdom. Last Activity: 6 Days Ago Has been a member for 7-8 years. Has a total post count of 692. Received thanks 29 times, giving thanks to others 0 times.
    check the earth for that drive, and as Rick has said swap the drives around to see if it's just the drive gone us.

  4. #4
    Hi Dan,

    I had similar glitching issues:

    It could be any number of things, but in my case I tracked it down to the power supply. It also occured at lower speeds, same as your problem. What drivers are you using? Are you microstepping?
    Building a CNC machine to make a better one since 2010 . . .
    MK1 (1st photo), MK2, MK3, MK4

  5. #5
    Many thanks; when I find time I will check over the next couple of evenings and let you know.


  6. #6
    OK, swapping the x and y drives over, dragged the problem with it.
    So it's not the stepper, and it's not mechanical :)
    It just means the X-axis driver is possibly goosed... I'll need to take the machine to bits and have a full-on gander...

    To be continued...

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