Welcome to Our Community

Some features disabled for guests. Register Today.

Help with a couple calibration questions?

Discussion in 'CNC Mills/Routers' started by iH8vols, Oct 23, 2017.

  1. iH8vols

    iH8vols Well-Known

    Dec 4, 2016
    Likes Received:
    My Ox CNC is getting closer (i think). I calibrated the x,y and z axis this weekend. I feel like the movement is pretty spot on. However, I did a test circle with a sharpie and my circle didn't quite close. Below is a link to a pic I took. I'm only worried about the part where the drawing started and ended. I haven't leveled my spoiler board yet. Circle with Pen:IMG_3112.JPG

    Also, I used a 3/4 diameter double flute to drill some holes in my MDF to use for holding work in place. As it was drilling the holes, I noticed the z axis would tilt very slightly as it began moving down into the wood. When the z axis finished and began raising, it would clear out the hole. Therefore when I put the dowel in, there's a small bit of separation in the front as you can see in this pic: IMG_3113.JPG

    It repeated this on every hole. Is this considered Backlash? Is there anything I can do to correct this? There's no wiggle on the z axis, so I don't think anything is loose.

    I use Universal G Code Sender. I don't believe there is a backlash adjustment available within it that I'm aware of.

    Below are my current GRBL settings. I would really appreciate any help or suggestions. Thanks!!

    GRBL Setting:

    $0=10 (step pulse, usec)
    $1=255 (step idle delay, msec)
    $2=0 (step port invert mask:00000000)
    $3=2 (dir port invert mask:00000010)
    $4=1 (step enable invert, bool)
    $5=0 (limit pins invert, bool)
    $6=0 (probe pin invert, bool)
    $10=3 (status report mask:00000011)
    $11=0.020 (junction deviation, mm)
    $12=0.002 (arc tolerance, mm)
    $13=0 (report inches, bool)
    $20=0 (soft limits, bool)
    $21=0 (hard limits, bool)
    $22=1 (homing cycle, bool)
    $23=0 (homing dir invert mask:00000000)
    $24=500.000 (homing feed, mm/min)
    $25=3000.000 (homing seek, mm/min)
    $26=244 (homing debounce, msec)
    $27=5.000 (homing pull-off, mm)
    $100=27.000 (x, step/mm)
    $101=26.634 (y, step/mm)
    $102=202.000 (z, step/mm)
    $110=4000.000 (x max rate, mm/min)
    $111=3000.000 (y max rate, mm/min)
    $112=1000.000 (z max rate, mm/min)
    $120=2000.000 (x accel, mm/sec^2)
    $121=2000.000 (y accel, mm/sec^2)
    $122=1000.000 (z accel, mm/sec^2)
    $130=1190.000 (x max travel, mm)
    $131=569.220 (y max travel, mm)
    $132=1000.000 (z max travel, mm)
  2. JustinTime

    JustinTime Master

    Dec 18, 2013
    Likes Received:
    It could be backlash but to tell for sure we need to see the complete circle. Level your bed and reprint it.

Share This Page