Internal error on command:"QUAD_GANTRY_LEVEL" ZeroDivisionError: float division by zero

[Troubleshooter]

Basic Information:

Printer Model: Modix Big-Metre
MCU / Printerboard: BTT Octopus v1.1
Host / SBC
klippy.log

Describe your issue:

I’m slowly migrating my Modix Big-metre over to Klipper. I’ve got most of the basic functions working. However, I’m running into an issue with “Quad Gantry Level”.

I home the machine and then run the QGL. It probes all four corners but on the last errors out. I get this Internal error on command:“QUAD_GANTRY_LEVEL”. Looking into my log I can see the following “ZeroDivisionError: float division by zero” Does anyone know what I can do to solve this?
klippy (6).log (136.3 KB)

Many thanks
…

[EddyMI3D]

Hello @Troubleshooter !

When you have 4 points, you need to have 4 gantry_corners:

[quad_gantry_level]
gantry_corners = 
	-203, -100
	1035, 1035
points = 
	50, 50
	935, 50
	935, 935
	50, 935
speed = 140
horizontal_move_z = 15
max_adjust = 15
retries = 20
retry_tolerance = 0.01

https://www.klipper3d.org/Config_Reference.html#quad_gantry_level

Also take care that the steppers are assigned to the correct corners as mentioned in the link

[Troubleshooter]

Hi, Thanks for the quick reply.

I’ve just added all four gantry_corners but still get the same error.
klippy (7).log (309.3 KB)

My machine homes to the back left (attached is my layout)

[EddyMI3D]

I don’t know if it works with that origin.

But do you see the difference:

 ----------------
 |Z1          Z2|
 |  ---------   |
 |  |       |   |
 |  |       |   |
 |  x--------   |
 |Z           Z3|
 ----------------

The way from Z to Z1 is along the Y-axis, not along the X-axis.

You may reassign the steppers.

[Troubleshooter]

So like this? and change the gantry_corners and points to suit.

[EddyMI3D]

Or just turn by 90° to the left.

[Troubleshooter]

Ok, thanks. I’ll give that a go tomorrow and report back

[Troubleshooter]

Thank you, that worked