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GRBL Settings and Bad Number Format

Discussion in 'Control Software' started by jkalberer41, Aug 23, 2016.

  1. jkalberer41

    jkalberer41 Well-Known
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    I have a Routy- type build going on, I've recently moved and not worked on it for a while. Before the move I was having trouble with the actual machine output being much larger than what it should be. Now I'm working on it again and I'm wondering if someone would take a look at my settings and point out anything that might be way off. I don't remember if I was messing with them aimlessly before packing up.

    $0=3 (step pulse, usec)
    $1=255 (step idle delay, msec)
    $2=0 (step port invert mask:00000000)
    $3=0 (dir port invert mask:00000000)
    $4=0 (step enable invert, bool)
    $5=0 (limit pins invert, bool)
    $6=0 (probe pin invert, bool)
    $10=3 (status report mask:00000011)
    $11=0.010 (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=0 (homing cycle, bool)
    $23=0 (homing dir invert mask:00000000)
    $24=25.000 (homing feed, mm/min)
    $25=500.000 (homing seek, mm/min)
    $26=250 (homing debounce, msec)
    $27=1.000 (homing pull-off, mm)
    $100=106.670 (x, step/mm)
    $101=106.670 (y, step/mm)
    $102=106.670 (z, step/mm)
    $110=500.000 (x max rate, mm/min)
    $111=500.000 (y max rate, mm/min)
    $112=500.000 (z max rate, mm/min)
    $120=10.000 (x accel, mm/sec^2)
    $121=10.000 (y accel, mm/sec^2)
    $122=10.000 (z accel, mm/sec^2)
    $130=200.000 (x max travel, mm)
    $131=200.000 (y max travel, mm)
    $132=200.000 (z max travel, mm)

    I'm running nema 17's on this baby, and GRBL v0.9. My projects are in mm, very much metric. In the meantime, I'm going to install my limit switches. Thanks.
     
  2. David the swarfer

    David the swarfer OpenBuilds Team
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    If output is too large then those values need to change UNLESS you are not including a G21 in your Gcode.
    G20 sets imperialmode
    G21 sets metric mode
    AND it gets remembered between runs, so every file should set what it needs!

    If you have G21 mode correctly set, then the steps/mm values need to be calibrated:
    HOWTO Calibrate your OX or C-Beam
     
  3. jkalberer41

    jkalberer41 Well-Known
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    How do I determine if G21 mode is correctly set? When typing in "$G" this is what comes up:

    Grbl 0.9j ['$' for help]
    [G0 G54 G17 G21 G90 G94 M0 M5 M9 T0 F0. S0.]
    ok
    ok
     
  4. David the swarfer

    David the swarfer OpenBuilds Team
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    well, that lists G21 as active.
    you can also give the command G21, just as you did for $G and that would set G21 active.

    So if that was already active, then the scaling issue is not a mm/inch thing, but rather the $100, $101 $102 calibration...
     
  5. jkalberer41

    jkalberer41 Well-Known
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    Ok, I'll go back through that, thank you very much.
     
  6. jkalberer41

    jkalberer41 Well-Known
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    So what I found is that my numbers there were way off. Incredibly far off. For the nema17's, with a step angle of 2.8, that would make 200 steps per revolution. the timing belt has a pitch of .66 and the pulley has 14 teeth.

    So for X and Y:

    200/.66/14 = 21.65

    Not 106.67

    And for Z:

    200/2 = 100

    Not 106.67

    I don't know what I was doing before, but thank you for bringing this to my attention. Does this all look correct to you? Do I need to add microsteps in the calculation somewhere?
     
    #6 jkalberer41, Aug 25, 2016
    Last edited: Aug 25, 2016

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