Define Origin Question

Troubleshooting
1

In step 10 of Using-the-Temporary-Frame-to-Cut-Parts it states to hit define origin, are we referring to define home or am I missing that define origin button

1 Like
2

Yepā€¦ Define Homeā€¦ we should update that (it confused me when I was new as well).

Edit: I updated the wiki.

7 Likes
3

+1 for editing the wiki @madgrizzle

2 Likes
4

Iā€™ve had a chance to look at workflow while i await a new power supply. As a SketchUp user Iā€™m going to try the Phlatboyz Sketchucam plug-in. This outputs tool paths that always originate from 0,0 of the ā€˜safe spaceā€™ (8ā€™x4ā€™ board). Can I just define this as origin in GC? Sorry, newb, with a self-build looking to make good his first ā€˜pieceā€™! ;Ā¬)

1 Like
5

GC defaults to 0,0 being the center of the workarea. You can move that ā€˜Homeā€™ point in several ways

  • by using the arrows to move to the desired spot and clicking ā€˜Define Homeā€™ when you arrive there
  • by click-holding on a spot and choosing ā€˜Move hereā€™, the ā€˜Define Homeā€™
  • by executing a gcode line like ā€œG01 X-15.0 Y-18.0ā€ either in a file or as a macro, then ā€˜Define Homeā€™
  • or last, by editing the Advanced Settings for ā€˜Home Positionā€™ (which changes it but doesnā€™t move you there)
  • beyond last, those ā€˜Home Positionā€™ values are found in groundcontrol.ini, so you could change them there when GC isnā€™t runningā€¦
2 Likes
6

Does changing the Home position change where the 0,0 is for the machine permanently, or just for the session? Or does it change the coordinates at all? I guess I am asking if Define Home is equivalent to defining a new origin of the coordinate system, and how long that change lasts.

1 Like
7

Changing the home position will move the gcode to the target location, and it will persist across closing and re-opening GC. Loading a new file will load at the same place.

The point of having the change persist is to make it easier to have multiple files align so for example if I run a cut and then realize that I forgot to generate gcode to drill some holes I can make a new file which just has the holes and run it and the alignment will be correct.

The position displayed in the digital position readout is always the absolute XY position, not the distance to the home position.

1 Like
8

Ok, I think that makes sense (and the underlying reason for it definitely makes sense). If I am understanding it properly, GC is applying an XY position modification to the gcode based upon where Home has been defined. However, you can drive the sled back to 0,0 and redefine home because the position readout remains unchanged.

Would I be correct in thinking that if I changed the Home position to be, say, -24,-24 that when the sled is located at that position entering in a command of G0 X0 Y0 would do nothing (i.e. the sled would not move)?

2 Likes
9

Iā€™m not in a position to check, but I think it persists. The fact that groundcontrol.ini can record it suggests this. Iā€™ll check later and report back :smile:
Edit - I see that @bar has answered already. Doing forum replies on the tiny screen is suboptimalā€¦

2 Likes