Auto Z zero Fail

X-Carve Troubleshooting
1

I installed a z zero toutch plate on my machine. the toutch plate has a wire going to pin a5 on the arduino board and there is a clamp going to my bit with a wire going to the negative terminal of my power supply where the spindle gets it power

I am using the grbl shield on an Arduino
The commands I am using are from charlie thomas
The machine moves very slowly for about 1/16 inch then stops and the UGS ver 1.0.8 says probe fail and alarm goes on
It does this for the z x and y
<img src=“//discuss-assets.s3.amazonaws.com/original/2X/e/eda8e9e458b68329e3cc434949fbb9ae65bd5bc3.png” width=“566” height=“475”

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if you want the excell work sheet i am using ill send it to you jusr send me your email
here is a video of what i did. this is not me i just got the idea from this video

youtube Auto Zero CNC X Y Z Axis

2

Are you using UGS to send the command? What command are you sending to use the plate?

3

yes i am using USG to send the command lets say my bit is 1/8 so .125 and my plats is 1/2 so .5
the first line of code i would run is for the x then y then z and it will look like this

x G38.2 X-.5 F1;G92 X0.0625
y G38.2 Y-.5 F1;G92 Y0.0625
z G38.2 Z-.5 F1;G92 Z0.5;G0 Z0.25

it moves 1/16 inch in said direction then UGS says probe fail and alarm on does not mater order xyz
yxz zxy ect same every time

4

Make sure under machine control tab you are set for inches…mine did the same thing.

5

And I don’t use the G0 Z0.25 command after zeroing the Z axis, I just jog the bit up a bit and start my project…

7

(I think someone else pointed out that you’re probably in metric, not fractional, so you’re moving 1mm not 1/16th of an inch.)

I use this UCS macro to adjust my settings:

g91; G20 ; G38.2 Z-1 F3; g10 p1 l20 z1; g54; g1 z.1; g21

Translated:
g91 - switch to relative mode
g21 - fractional instead of metric (I use a 1-2-3 block that’s 1" high as a touchplate)
G38.2 Z-1 F3 probe down one inch (that’s the -1) at a feed rate of 3" per minute
g10 p1 l20 z1 - set the Z work coordinate for the G54 workspace to one inch below its current position (since I know my touchplate is 1" thick). I set my X and Y somewhere else, not using a probe. [You want to look at Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable for the g10 documentation. Be prepared to cry/laugh; gcode pays no attention to any sort of sensible software design.]
g54 use the G54 workspace
g1 z.1 move up one tenth of an inch off the touchplate
g21 switch back to real measurements (aka metric).

I think the a problem you have is that you’re adjusting your machine coordinates. Those shouldn’t change; you should adjust a workspace instead.

8

If you’re using UGS, “jog the bit up” is a button or keystroke that sends g91 g0 [something] to the Arduino. It’s doing the same thing.

9

You are correct, it is just not a part of my macro.

10

Ok got it fixed by finding a faulty ground in the clip end that goes to my bit. Auto z zero now works. Do I need a 4th line of code to bring it to true z zero or will it just know where it is because of the zeroing process