Help understanding the Origin and 'Prepare' coordinates

[arhodiewithsoul 0]

Hi all,

 

I've been writing a custom profile for my printer, but am struggling to wrap my head around the displayed co-ordinates '(Move (T)' panel and Origin in the main 'Prepare' view.

 

1. When I load Cura (3.5.1), I can see my build plate displays correctly, but the Origin icon appears at the Front, Left. I know my printer's origin is Rear, Right - but I cannot find any setting to define the Origin icon to display in the correct place.

 

2. When I load a model, it drops to the center of the BuildPlate/PrintBed and calls that 0,0 despite specifying "machine_center_is_zero" is "default_value": false.

:: If I 'Move (T)' the model in X, it's a positive movement to the Right (ie. +100), negative to the Left (ie. -100)

:: If I 'Move (T)' the model in Y, it's a positive movement to the Front (ie. +100), negative to the Rear (ie. -100)

This behaviour is the same whether I then select 'Origin at center', or not, from within 'Machine Settings'

 

Ideally, I would like the Origin to be displayed in the Rear, Right corner and when moving an object the 'Move (T)' panel would show Front, Left as 200, 200 

 

Is anyone able to assist?

 

many thanks

 

ARWS

[nallath 1,120]

Display wise, Cura always assumes that the center of the build plate is the (0,0) origin (So; if you use the move tool, that's the location where it's moving from!)
 

The machine_center_is_zero basically defines if this assumption is true. For most printers, this is not the case, since they tend to use the lower left corner for the 0,0.

 

That being said; What you want isn't possible without code changes.

[arhodiewithsoul 0]

11 minutes ago, nallath said:

Display wise, Cura always assumes that the center of the build plate is the (0,0) origin (So; if you use the move tool, that's the location where it's moving from!)
 

The machine_center_is_zero basically defines if this assumption is true. For most printers, this is not the case, since they tend to use the lower left corner for the 0,0.

 

That being said; What you want isn't possible without code changes.

 

Thanks for your quick reply!

 

Could I ask: When you say 'code changes' - do you mean to Cura itself?

 

As a solution to the Origin icon: If I rotate my platform_OBJ by 180 degrees around the vertical, the Origin icon will be in the correct position, but when loading Cura I'll initially see the back of the printbed (?) If so, I can live with that.

 

For me to try to understand the Cura display co-ordinates when moving the object: Are you saying that the object co-ordinates displayed when moving around on the print bed bear no relation to the machine xy co-ordinates produced in the gcode?

[ahoeben 1,948]

The indicator should be seen as a “front-left indicator” instead of an origin (except for delta machines, which normally are the only machines that have the origin at the center). Don’t pay too much attention to it, since it doesn’t “do” anything except indication the front-left.

[arhodiewithsoul 0]

Thanks for getting back to me, I appreciate you guys taking the time to respond.

 

Other Cura users had noted that when they'd set up their custom profiles for the daVinci machines, the objects would load back to front. By this, I mean that an object placed near the Front, Left indicator would actually print in the Rear, Right location.

 

I have tested this behaviour by placing objects on the 'Normal' build plate and slicing, then rotating my build plate in the OBJ file 180degrees to change the indicator's position and slicing again. Both files were then separately reviewed in the native XYZware printing program to compare the two outputs. 

 

Objects aligned to the Front, Left indicator actually locate in the Rear, Right.

 

The rotated build plate correctly shows objects near the daVinci's Origin (which is Rear, Right). I am happy to leave my build plate rotated, that way what I see is what I get when the Object prints.

 

This output clearly shows that Cura inherently designates the 'indicator' as an Actual Origin.

Edited November 16, 2018 by arhodiewithsoul
Clarifying explanation

[arhodiewithsoul 0]

For me, the co-ordinates displayed in the Move panel make sense only if your Origin is set to the Centre of the plate. Otherwise the information is somewhat superfluous. Wouldn't it make more sense that the centre of the Object displays co-ordinates relative to the Origin?