Mpcnc skr touch probe code

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1

Hello I was wondering if someone could post the start code they use on their mpcnc with a skrpro board with dual end stops and a touch probe. I haven’t used mine in a while and I can’t seem to find it. I know it’s a bit different than my lr3. If anyone could post a quick pic that would be super handy.

2

I don’t have one, but in case this helps…

https://docs.v1e.com/tools/milling-basics/#starting-gcode

There are MPCNC-Marlin versions for start, end, and tool change

3

Thanks you I looked on the docs and did try searching.
This is exactly what I need ;).

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4

Sorry to hijack the thread but I think its close enough to be useful. in the start G-Code I don’t understand the G28 line or at least the X Y part. the steps as I understand it

  1. manual home
  2. manual jog to start point
  3. Start job with a z probe … hit continue

the code for reference

G92 X0 Y0 Z0 ; Set Current position to 0, all axes
G00 Z5.0000 F500 ; Raise Z 5mm at 8.3mm/s to clear clamps and screws
G28 X Y Z ; Home in order, with Z touchplate
G92 Z0.5 ; Account for probe thickness (set your thickness)
G00 Z5.000 F500 ; Raise Z probe off of surface
M00 ; Pause for LCD button press so you can remove the touchplate

5

The code, line by line, does the following

G92 X0 Y0 Z0 ; Set Current position to 0, all axes
Sets the current position as 0,0,0 across all axes.

G00 Z5.0000 F500 ; Raise Z 5mm at 8.3mm/s to clear clamps and screws
Raise the toolhead by 5mm

G28 X Y Z ; Home in order, with Z touchplate
Home X, Home Y, then Home Z.

G92 Z0.5 ; Account for probe thickness (set your thickness)
Homing Z was done with the touch plate as the stop, so set the current position to the thickness of the touch probe so 0 is actually the top of the workpiece.

Now, above the gcode, it says:
“On the MPCNC you will typically home the XY axes before starting your job and drive the machine with the control panel to the starting position. This gcode would then run to reset the coordinates and probe the surface.”

So it sounds like it expects you to already be at whatever X, Y coordinate you want to start at, so perhaps the X Y in the G28 line is a mistake??

Perhaps @vicious1 can clarify. I would have expected only a Z home there if the idea is that manually homing, and then moving to your desired starting position before starting was the goal.

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6

Yeah that G28 should not be there. Lemme go fix that.

7

Should just be

G28 Z

for the MPCNC

8

fixed

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9

Weird bc it works perfect in my machine with the g28 x y z.
Ohh I can see now lol
I am using the machine to bring itself home with dual end stops.
If I wanted to start the machine anywhere specifically then I would not use the g28 x y z but just g28 z ?
Also if I use the tft terminal and enter g28 it brings it all home as if I had entered g28 x y z

10

The default behavior is to home all axes. G28 and G28 X Y Z are functionally the same.

Correct. The gcode has been updated for MPCNC - Marlin in the Docs to :

G92 X0 Y0 Z0 ; Set Current position to 0, all axes
G00 Z5.0000 F500 ; Raise Z 5mm at 8.3mm/s to clear clamps and screws
G28 Z ; Home Z touchplate
G92 Z0.5 ; Account for probe thickness (set your thickness)
G00 Z5.000 F500 ; Raise Z probe off of surface
M00 ; Pause for LCD button press so you can remove the touchplate
3 Likes
11

Thank you guys for explaining it!

1 Like
12

thanks from me too