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Limit switches board V3 GRBL V1.1

Posted: Sun Apr 30, 2017 9:24 am
by jnivard
I am building a small CNC machine using a crostable and
I use CNC shield version 3.0 and try to use GRBL 1.1 and the UGS.

I can move the tabel but have problems withe the limit switches

I rewired the wire from the Z + limit switch to SpnEnd.
I did set $21=1
When I measure the voltage on the pins, I have 4,6V on
1-SpnEnd = 4,6 (z+)
2-x- = 4,6
3 x+ =4,6
4 y- = 4,6
5 y+ = 4,6
6 z- = 0 ????????????

I do not understand why the z- = 0. Who can help?


$0=10 (step pulse, usec)
$1=25 (step idle delay, msec)
$2=0 (step port invert mask:00000000)
$3=1 (dir port invert mask:00000001)
$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=1 (hard limits, bool)
$22=1 (homing cycle, bool)
$23=7 (homing dir invert mask:00000111)
$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=3200.000 (x, step/mm)
$101=3200.000 (y, step/mm)
$102=3200.000 (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=3200.000 (x max travel, mm)
$131=2700.000 (y max travel, mm)
$132=750.000 (z max travel, mm)

Re: Limit switches board V3 GRBL V1.1

Posted: Tue Oct 03, 2017 8:56 am
by StoneAgeSkillz
I know it's an older question and i think you have figured it out by now. But still:

Shield v3.0 and GRBL 1.1 - Z- (Z minus) is actualy Spindle PWM/EN. It is on Arduino D11 pin. PWM enabled with $32=1.

I'm using it for laser PWM.

There, thats it.

Re: Limit switches board V3 GRBL V1.1

Posted: Wed Oct 04, 2017 6:17 pm
by jnivard
Yes I had a old version. I did by the new version and now all is working ok

Thanks for the reply

I am building now a improved version of my CNC designing a crossable and I like the
idee of the touch probe or I like the idee of doing some image processing.

he goal is to have a CNC machine that I can use to make "wing" of a airplane



Re: Limit switches board V3 GRBL V1.1

Posted: Sun Nov 26, 2017 3:02 am
by regpye
I am setting up the same configuration, a CNC shield v3 with GRBL 1.1f
I am confused about how to wire the laser module and also use a Z axis with Z limit stop.
I want to be able to use the Z axis to raise and lower the laser, but also to be able to control the laser itself.
Not sure what connections to use. The spindle is now the Z limit?? Not sure, it doesn't seem to be clearly explained anywhere that I can find.