bCNC problem or user error

I got bCNC all setup (because I wanted to use something with a WCS) and everything seemed to be going fine, I set the x,y,z for G54 moved it off and issued command to send it back, works perfectly…

Then I try and run some Gcode and when it starts it send the gantry all the way back to the home location in the top right triggering the one of the switches… what am I doing wrong? Why is it not using my new zero on G54? Is there a secondary (or primary) 0 you have to set outside of the WCS setup?

As I understand it G54 is reserved for the base position or something like that. Use G55-59 and they should work.

Specifically, G54 is reserved by Carbide3D for use in Carbide Motion to manage / record machine position — if you’re using Carbide Motion at all, or think you might in the future, don’t use it.

I have had that kind of odd movement w/ certain unsupported G-codes: http://www.shapeoko.com/wiki/index.php/G-Code#G-code_Not_supported_by_Grbl

What is in the beginning of your Gcode? Is it selecting a WCS? Issuing a G92?

It is whatever Fusion 360 generates…(genaric GRBL post) I’ll look at it when I get home to see if there is an odd code there but I’ve run the same codes through carbide motion and it works fine with whatever zero I set. Would that explain anything?

No, I’d need to see the gcode.

I’ll post it when I get home in approximately … 7.5 hours

Use the Carbide post

98% sure I did use that on the post… I couldn’t find a list online for post processes on fusion 360 to look though for the exact name.

You had listed generic grbl. That is different then the carbide one. It should be an option in the dropdown list.

Right but I’m at work and can’t look at the list at the moment and could only remember generic grbl.

%
(R1x4 mount)
(R1x4 mount)
(T3 D=3.175 CR=1.587 - ZMIN=0 - ball end mill)
G90
G17
G21
G28 G91 Z0
G90

(2D Contour2)
M9
T3 M6
S8000 M3
G54
M7
G0 X-30.742 Y-0.301
Z26
Z16
G1 Z15 F609.6
Z8.317 F762
X-30.734 Z8.247
X-30.711 Z8.18
X-30.673 Y-0.3 Z8.12
X-30.623 Y-0.299 Z8.069
X-30.563 Y-0.297 Z8.031
X-30.496 Y-0.295 Z8.008
X-30.425 Y-0.294 Z8
X-30.108 Y-0.286 F609.6
G3 X-29.798 Y0.039 I-0.008 J0.317
X-33.002 Y-0.039 I-1.602 J-0.039
X-29.798 Y0.039 I1.602 J0.039
X-30.123 Y0.349 I-0.317 J-0.008
G1 X-30.441 Y0.341
X-30.511 Y0.339 Z8.008
X-30.578 Y0.338 Z8.031
X-30.638 Y0.336 Z8.069
X-30.689 Y0.335 Z8.12
X-30.727 Y0.334 Z8.18
X-30.75 Z8.247
X-30.758 Y0.333 Z8.317
X-30.742 Y-0.301
Z5.317 F762
X-30.734 Z5.247
X-30.711 Z5.18
X-30.673 Y-0.3 Z5.12
X-30.623 Y-0.299 Z5.069
X-30.563 Y-0.297 Z5.031
X-30.496 Y-0.295 Z5.008
X-30.425 Y-0.294 Z5
X-30.108 Y-0.286 F609.6
G3 X-29.798 Y0.039 I-0.008 J0.317
X-33.002 Y-0.039 I-1.602 J-0.039
X-29.798 Y0.039 I1.602 J0.039
X-30.123 Y0.349 I-0.317 J-0.008
G1 X-30.441 Y0.341
X-30.511 Y0.339 Z5.008
X-30.578 Y0.338 Z5.031
X-30.638 Y0.336 Z5.069
X-30.689 Y0.335 Z5.12
X-30.727 Y0.334 Z5.18
X-30.75 Z5.247
X-30.758 Y0.333 Z5.317
X-30.742 Y-0.301
Z2.317 F762
X-30.734 Z2.247
X-30.711 Z2.18
X-30.673 Y-0.3 Z2.12
X-30.623 Y-0.299 Z2.069
X-30.563 Y-0.297 Z2.031
X-30.496 Y-0.295 Z2.008
X-30.425 Y-0.294 Z2
X-30.108 Y-0.286 F609.6
G3 X-29.798 Y0.039 I-0.008 J0.317
X-33.002 Y-0.039 I-1.602 J-0.039
X-29.798 Y0.039 I1.602 J0.039
X-30.123 Y0.349 I-0.317 J-0.008
G1 X-30.441 Y0.341
X-30.511 Y0.339 Z2.008
X-30.578 Y0.338 Z2.031
X-30.638 Y0.336 Z2.069
X-30.689 Y0.335 Z2.12
X-30.727 Y0.334 Z2.18
X-30.75 Z2.247
X-30.758 Y0.333 Z2.317
X-30.742 Y-0.301
Z0.317 F762
X-30.734 Z0.247
X-30.711 Z0.18
X-30.673 Y-0.3 Z0.12
X-30.623 Y-0.299 Z0.069
X-30.563 Y-0.297 Z0.031
X-30.496 Y-0.295 Z0.008
X-30.425 Y-0.294 Z0
X-30.108 Y-0.286 F609.6
G3 X-29.798 Y0.039 I-0.008 J0.317
X-33.002 Y-0.039 I-1.602 J-0.039
X-29.798 Y0.039 I1.602 J0.039
X-30.123 Y0.349 I-0.317 J-0.008
G1 X-30.441 Y0.341
X-30.511 Y0.339 Z0.008
X-30.578 Y0.338 Z0.031
X-30.638 Y0.336 Z0.069
X-30.689 Y0.335 Z0.12
X-30.727 Y0.334 Z0.18
X-30.75 Z0.247
X-30.758 Y0.333 Z0.317
G0 Z16
X0.658 Y31.104
G1 Z15 F609.6
Z8.317 F762
X0.666 Y31.105 Z8.247
X0.689 Z8.18
X0.727 Y31.106 Z8.12
X0.777 Y31.107 Z8.069
X0.837 Y31.109 Z8.031
X0.904 Y31.11 Z8.008
X0.975 Y31.112 Z8
X1.292 Y31.12 F609.6
G3 X1.602 Y31.445 I-0.008 J0.317
X-1.602 Y31.366 I-1.602 J-0.039
X1.602 Y31.445 I1.602 J0.039
X1.277 Y31.755 I-0.317 J-0.008
G1 X0.959 Y31.747
X0.889 Y31.745 Z8.008
X0.822 Y31.744 Z8.031
X0.762 Y31.742 Z8.069
X0.711 Y31.741 Z8.12
X0.673 Y31.74 Z8.18
X0.65 Y31.739 Z8.247
X0.642 Z8.317
X0.658 Y31.104
Z5.317 F762
X0.666 Y31.105 Z5.247
X0.689 Z5.18
X0.727 Y31.106 Z5.12
X0.777 Y31.107 Z5.069
X0.837 Y31.109 Z5.031
X0.904 Y31.11 Z5.008
X0.975 Y31.112 Z5
X1.292 Y31.12 F609.6
G3 X1.602 Y31.445 I-0.008 J0.317
X-1.602 Y31.366 I-1.602 J-0.039
X1.602 Y31.445 I1.602 J0.039
X1.277 Y31.755 I-0.317 J-0.008
G1 X0.959 Y31.747
X0.889 Y31.745 Z5.008
X0.822 Y31.744 Z5.031
X0.762 Y31.742 Z5.069
X0.711 Y31.741 Z5.12
X0.673 Y31.74 Z5.18
X0.65 Y31.739 Z5.247
X0.642 Z5.317
X0.658 Y31.104
Z2.317 F762
X0.666 Y31.105 Z2.247
X0.689 Z2.18
X0.727 Y31.106 Z2.12
X0.777 Y31.107 Z2.069
X0.837 Y31.109 Z2.031
X0.904 Y31.11 Z2.008
X0.975 Y31.112 Z2
X1.292 Y31.12 F609.6
G3 X1.602 Y31.445 I-0.008 J0.317
X-1.602 Y31.366 I-1.602 J-0.039
X1.602 Y31.445 I1.602 J0.039
X1.277 Y31.755 I-0.317 J-0.008
G1 X0.959 Y31.747
X0.889 Y31.745 Z2.008
X0.822 Y31.744 Z2.031
X0.762 Y31.742 Z2.069
X0.711 Y31.741 Z2.12
X0.673 Y31.74 Z2.18
X0.65 Y31.739 Z2.247
X0.642 Z2.317
X0.658 Y31.104
Z0.317 F762
X0.666 Y31.105 Z0.247
X0.689 Z0.18
X0.727 Y31.106 Z0.12
X0.777 Y31.107 Z0.069
X0.837 Y31.109 Z0.031
X0.904 Y31.11 Z0.008
X0.975 Y31.112 Z0
X1.292 Y31.12 F609.6
G3 X1.602 Y31.445 I-0.008 J0.317
X-1.602 Y31.366 I-1.602 J-0.039
X1.602 Y31.445 I1.602 J0.039
X1.277 Y31.755 I-0.317 J-0.008
G1 X0.959 Y31.747
X0.889 Y31.745 Z0.008
X0.822 Y31.744 Z0.031
X0.762 Y31.742 Z0.069
X0.711 Y31.741 Z0.12
X0.673 Y31.74 Z0.18
X0.65 Y31.739 Z0.247
X0.642 Z0.317
G0 Z16
X32.05 Y-0.317
G1 Z15 F609.6
Z8.317 F762
G18 G2 X32.368 Z8 I0.318 K0
G1 X32.685 F609.6
G17 G3 X33.002 Y0 I0 J0.317
X29.798 I-1.602 J0
X33.002 I1.602 J0
X32.685 Y0.318 I-0.317 J0
G1 X32.368
G18 G3 X32.05 Z8.317 I0 K0.318
G1 Y-0.317
Z5.317 F762
G2 X32.368 Z5 I0.318 K0
G1 X32.685 F609.6
G17 G3 X33.002 Y0 I0 J0.317
X29.798 I-1.602 J0
X33.002 I1.602 J0
X32.685 Y0.318 I-0.317 J0
G1 X32.368
G18 G3 X32.05 Z5.317 I0 K0.318
G1 Y-0.317
Z2.317 F762
G2 X32.368 Z2 I0.318 K0
G1 X32.685 F609.6
G17 G3 X33.002 Y0 I0 J0.317
X29.798 I-1.602 J0
X33.002 I1.602 J0
X32.685 Y0.318 I-0.317 J0
G1 X32.368
G18 G3 X32.05 Z2.317 I0 K0.318
G1 Y-0.317
Z0.317 F762
G2 X32.368 Z0 I0.318 K0
G1 X32.685 F609.6
G17 G3 X33.002 Y0 I0 J0.317
X29.798 I-1.602 J0
X33.002 I1.602 J0
X32.685 Y0.318 I-0.317 J0
G1 X32.368
G18 G3 X32.05 Z0.317 I0 K0.317
G0 Z16
X0.65 Y-31.723
G1 Z15 F609.6
Z8.317 F762
G2 X0.967 Z8 I0.317 K0
G1 X1.285 F609.6
G17 G3 X1.602 Y-31.406 I0 J0.318
X-1.603 I-1.602 J0
X1.602 I1.602 J0
X1.285 Y-31.088 I-0.317 J0
G1 X0.967
G18 G3 X0.65 Z8.317 I0 K0.318
G1 Y-31.723
Z5.317 F762
G2 X0.967 Z5 I0.317 K0
G1 X1.285 F609.6
G17 G3 X1.602 Y-31.406 I0 J0.318
X-1.603 I-1.602 J0
X1.602 I1.602 J0
X1.285 Y-31.088 I-0.317 J0
G1 X0.967
G18 G3 X0.65 Z5.317 I0 K0.318
G1 Y-31.723
Z2.317 F762
G2 X0.967 Z2 I0.317 K0
G1 X1.285 F609.6
G17 G3 X1.602 Y-31.406 I0 J0.318
X-1.603 I-1.602 J0
X1.602 I1.602 J0
X1.285 Y-31.088 I-0.317 J0
G1 X0.967
G18 G3 X0.65 Z2.317 I0 K0.318
G1 Y-31.723
Z0.317 F762
G2 X0.967 Z0 I0.317 K0
G1 X1.285 F609.6
G17 G3 X1.602 Y-31.406 I0 J0.318
X-1.603 I-1.602 J0
X1.602 I1.602 J0
X1.285 Y-31.088 I-0.317 J0
G1 X0.967
G18 G3 X0.65 Z0.317 I0 K0.317
G0 Z26
G17
M9
G28 G91 Z0
G28 X0 Y0
M30
%

Please help I’m at a standstill till i can figure this out

%
(R1x4 mount)
(R1x4 mount)
(T3 D=3.175 CR=1.587 - ZMIN=0 - ball end mill)
G90 <- Absolute Mode
G17 <- XY Plane
G21 <- Units to MM
G28 G91 Z0 <- Return to Home, Relative Mode, go to Z0
G90 <- Absolute Mode

(2D Contour2)
M9 <- Coolant off
T3 M6 <- Tool change, load tool #3 (not supported)
S8000 M3 <- Turn on the spindle
G54 <- Select G54 WCS
M7 <- Coolant on
G0 X-30.742 Y-0.301
Z26
Z16
G1 Z15 F609.6
Z8.317 F762
X-30.734 Z8.247

I marked up your code a little. I think your problem is the G28 in line 8. That sends the machine back to machine zero, which is right on the limit switches.

You should be able to just remove that line and it will work fine.

I would also take out the tool change line - I think that might trigger an unsupported g-code error, but I’m not sure.

1 Like

Thank you sir, I’ll start with removing the G28 first and move forward from there.

Works now, Thank you!

Glad to help! It’s always good to read the gcode and figure out what it’s actually doing.