XCarve will not complete Home sequence

This problem just started for me. When my Z axis hits the limit switch during the Easel homing sequence, it reverses direction, plunging into the table if not stopped. This used to work fine, only difference is I started learning how to use UGS (which I like!). When I try a home sequence in UGS, the limit switch does not seem to stop the Z axis when it hits it. The switch is still working when tested on a multi meter.

I can still use the XCarve, but not being able to home it kind of bugs me. Any thoughts?

Easel settings:

$0=10 (step pulse, usec)
$1=255 (step idle delay, msec)
$2=0 (step port invert mask:00000000)
$3=3 (dir port invert mask:00000011)
$4=0 (step enable invert, bool)
$5=0 (limit pins invert, bool)
$6=0 (probe pin invert, bool)
$10=115 (status report mask:01110011)
$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=3 (homing dir invert mask:00000011)
$24=1000.000 (homing feed, mm/min)
$25=1000.000 (homing seek, mm/min)
$26=250 (homing debounce, msec)
$27=300.000 (homing pull-off, mm)
$30=1. (rpm max)
$31=0. (rpm min)
$100=40.000 (x, step/mm)
$101=40.000 (y, step/mm)
$102=188.976 (z, step/mm)
$110=8000.000 (x max rate, mm/min)
$111=8000.000 (y max rate, mm/min)
$112=500.000 (z max rate, mm/min)
$120=500.000 (x accel, mm/sec^2)
$121=500.000 (y accel, mm/sec^2)
$122=50.000 (z accel, mm/sec^2)
$130=540.000 (x max travel, mm)
$131=540.000 (y max travel, mm)
$132=100.000 (z max travel, mm)

Check the wiring for your Z axis starting at the gShield/X-controller all the way to the Z stepper motor… Look for loose wires or wire strands shorting to a neighboring terminal.

Your $24 and $25 settings are high. Did you change them, or was that the default?

$27=300.000 (homing pull-off, mm)
This is likely causing your Z plunge when homing. Change it to:
$27=1.000 (homing pull-off, mm)

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Good catch. I missed that.

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Thank you very much for the replies. I will look into these settings and report back.

@CarySporinsky

Here are the defaults for the homing settings:

$24=25.000
$25=750.000
$26=250
$27=1.000

I also recommend to people that use homing to set “soft limits” on

$20=1

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Yes, that fixed it right up. I saw that setting yesterday and thought it was the cause but I did not know how to make changes to these settings. I learned how to do that now… thanks very much! Not sure how they were changed unless I did something in UGrbl.

I do note that my Y axis is very loud now, but only during the Home procedure. If I jog it is quite smooth… I almost wonder if the steppers are fighting against each other.

$0=10 (step pulse, usec)
$1=255 (step idle delay, msec)
$2=0 (step port invert mask:00000000)
$3=3 (dir port invert mask:00000011)
$4=0 (step enable invert, bool)
$5=0 (limit pins invert, bool)
$6=0 (probe pin invert, bool)
$10=115 (status report mask:01110011)
$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=3 (homing dir invert mask:00000011)
$24=300.000 (homing feed, mm/min)
$25=300.000 (homing seek, mm/min)
$26=250 (homing debounce, msec)
$27=1.000 (homing pull-off, mm)
$30=1. (rpm max)
$31=0. (rpm min)
$100=40.000 (x, step/mm)
$101=40.000 (y, step/mm)
$102=188.976 (z, step/mm)
$110=8000.000 (x max rate, mm/min)
$111=8000.000 (y max rate, mm/min)
$112=500.000 (z max rate, mm/min)
$120=500.000 (x accel, mm/sec^2)
$121=500.000 (y accel, mm/sec^2)
$122=50.000 (z accel, mm/sec^2)
$130=540.000 (x max travel, mm)
$131=540.000 (y max travel, mm)
$132=100.000 (z max travel, mm)

Thanks again for latest replies. Larry: I have set to those defaults now. TY.

added later: Those defaults made the Y Axis smooth and quiet again.