setting home position

[BROG 0]

Even though the model is positioned in the centre of the build plate in Cura review, when I start the printer it moves over the the side and runs off the plate!!!! How do you reset the printer home position? does it have a relationship with the Cura review ?

Thanks

G

[GregValiant 1,411]

Yes, there is a relationship.  Check in Cura and see if "Origin at Center" is checked.  For most cartesian printers (rectangular build plates) the origin is in the left front corner and that box should be un-checked.  For delta type printers the origin is usually at center.

 

So there is a relationship but it's platonic as neither Cura nor the printer have any idea where the build plate is in space.  They must be told.  Cura uses the "Origin at Center" check box and the build plate size "X(width)" and "Y(depth)" to describe the build plate and the Z(height) to make it a build volume.  The printer usually uses the end stop switches (auto-home location) coupled with the Home Offset position to determine where a gcode file should be placed in space.

 

Cura builds the gcode locations around the 0,0,0 Origin.  When the printer reads the gcode file it puts those numbers around ITS 0,0,0 Origin.  That location must be must agree both in Cura and in the printer.

You can check a gcode file by opening it in a text editor and looking at the beginning of the file for the lines:

;MINX:85.157
;MINY:99.699
;MINZ:0.2
;MAXX:144.845
;MAXY:130.301
;MAXZ:48

In that example all the numbers are positive and my Ender 3 Pro prints in the "positive octant" so they are correct.  If I had checked "Origin at Center" then the numbers for that same slice would be something like:

;MINX:-29.834
;MINY:-15.301
;MINZ:0.2
;MAXX:29.834
;MAXY:15.301
;MAXZ:48

Going a bit further, from the first example the midpoint of the model footprint is at "((MaxX - MinX)/2) + MinX" or X=115.00 and Y=115.00 which is the midpoint of my 230 x 230 bed.  In the second example the midpoint of the print is at MinX + MaxX or X=0 Y=0 and my printer would attempt to reach the negative numbers which would result in it moving to the left front corner and banging and clanging and spewing plastic and making awful noises while it tries to get to negative locations that it cannot.

I have to stop now because the coffee is done.

[BROG 0]

Thank you, Greg, very clear and concise, a great help.

G

[BROG 0]

Hi again Greg,

I am a newby, and I put the second lot of gcode (-29.834 etc) into Cura but the printer ( Ender 3 ) still goes to the bottom left of the plate, runs two lines just inside the y axis, then tries to do the prinr commencing there as well!!! What am I doing wrong? I am sure the printer settings are not compatible but cannot seem to change them! The read out states "too far out"!!!

HELP

G

[GregValiant 1,411]

That is gcode generated by Cura and not part of your "StartUp G-Code".

When you go to "Manage Printers" and "Machine Settings" is the "Origin at Center" box definitely NOT checked?

What printer do you have?

Please slice a calibration cube or benchy and post the gcode file here.

Edited January 7, 2022 by GregValiant

[braddach 0]

I'm having the same issue so when I load the STL I go straight to the printer set up and the origin at center box is checked in a few seconds the screen will refresh itself with the box unchecked so I go ahead and splice and when I go to print on my Ender3 V1 it gives me the outside billed area error message

[GregValiant 1,411]

@braddach you have to give us something to work with here.

What version of Cura?  Early versions of 5.x had issues with the Machine Settings dialog box not saving changes.  A workaround was to make your change and then click somewhere else (like in the Ending Gcode box) to set the change before closing the dialog.

 

Load a simple model, set up to slice, and use the "File | Save Project" command and then post the 3mf file here.