[muldoon22]

I know these questions have probably been asked a lot before, but I cannot figure out what is going on.

I’m using the following:
Grbl 1.1h
CNC 3 board
Grbl Panel 1.0.9.18
Solidworks 2021

I’ve gotten to the point where I can use the Home Cycle button to zero the machine using 3 endstops and offset all of them 6.35mm. The values say -6.35. When I go to make a simple test part (a 200mm x 200mm square) so I can (re)adjust the X/Y/Z step/mm values, it always wants to cut in the nonexistent positive portion of the workspace.

Is it ‘standard’ to have the workspace be all negative?

I’ve noticed that if I ‘zero’ the machine in the opposite corner of where the (0,0) is that I can sometimes cut a part, but it doesn’t seem right. By ‘zeroing’ the machine I just reset the Arduino the 3 smaller sized numbers are (0,0,0) when I reconnect.

I’ve also tried changing the coordinate system in Solidworks, but it never changes anything...



Using the endstops, should I be able to just start cutting the following the sample gcode?

N1 G20
N2 (1/4 EM CRB 2FL 3/4  LOC)
N3 G91 G28 X0 Y0 Z0
N4 T01 M06
N5 S12000 M03


N6 ( Contour Mill1 )
N7 G90 G54 G00 X-1.3677 Y-.3102
N8 G43 Z.1 H01 M08
N9 G01 Z-.125 F16.2
N10 G41 D21 X-1.3677 Y-.4402 F48.6
N11 G17 G03 X-1.375 Y-.4579 I.0177 J-.0177
N12 G01 Y-1.875 F64.8
N13 X1.375
N14 Y.9378
N15 X.0679 Y1.9264
N16 X-1.375 Y.9343
N17 Y-.4829
N18 G03 X-1.3677 Y-.5006 I.025 J0
N19 G40 G01 Y-.6306
N20 G00 Z.1
N21 X-1.3723 Y-.6282
N22 G01 Z-.125 F16.2
N23 G41 D21 X-1.3723 Y-.4982 F48.6
N24 G03 X-1.365 Y-.4805 I-.0177 J.0177
N25 G01 Y.929 F64.8
N26 X.0676 Y1.9141
N27 X1.374 Y.926
N28 Y-1.865
N29 X-1.365
N30 Y-.4555
N31 G03 X-1.3723 Y-.4378 I-.025 J0
N32 G40 G01 Y-.3078
N33 G00 Z.1
N34 Z1. M09
N35 G91 G28 Z0
N36 G28 X0 Y0
N37 M30

[hfjbuis]

Grbl has a Wiki page about homing. https://github.com/gnea/grbl/wiki/Se...ming-direction

Default setting ($23=0), the home location is the top right of your work area, with the spindle all the way up.

[muldoon22]

I've read up on $23 but my homing is working correctly. When I press the Home button the spindle moves up and hits the limit switch, and then it zeros at the X and Y by hitting their limit switches.

The problem is that whenever it Homes that the part is seems like it always wants to be made in the nonexistent positive workspace. When it starts, it instantly hits the limit switch and stops.

[machinehop5]

...need to set your G54 Work Coordinate. Home the xyz then Jog to where X0 Y0 should be on your part. Then store those values in the G54 Offsets.

[muldoon22]

Thanks for your answer!
I looked into the G54 and I learned that that pressing the ZERO XYZ button was part of the problem. Even when I was pressing the button and it was zeroed, that it was still moving back the home location and triggering the X and Y limit switches; which stopped the code (which it should). This spurred me to further look into the gcode that was produced. I quickly noticed that at the beginning of the code there was this line.

N3 G91 G28 X0 Y0 Z0

Deleting this line made it start behaving as I was expecting!

Now I have to look into Solidworks CAM and find out how to fix it so it doesn't always happen.