[AVRnj]

So I ran my first program today in metal, ran a few in wax and all went fine.

At the end of a contour 2d tool path, my end mill plunged through my aluminum and into my vice, destroying an expensive end mill, and ruining my vice jaw.

Looking at the code that did it, I don't quite understand why.

I am running Mach3, so I used the generic Mach3 post in Fusion 360.

Can anyone help me understand what happened? It happened somewhere between the last 2 or 3 lines of this code below. Any help would be greatly appreciated! I looked up the codes and its not clear to me why this happened.

(2D CONTOUR1)
M5
M9
M1
T31 M6
S2300 M3
G54
M8
G0 X1.5675 Y0.2935
G43 Z0.6 H31
Z0.2
G1 Z0.0394 F5.
Z-1.6729 F4.
G19 G2 Y0.2435 Z-1.7229 J-0.05 K0.
G1 Y0.1935 F5.
G17 G3 X1.6175 Y0.1435 I0.05 J0.
G1 X3.1136 F9.
G2 X3.3636 Y-0.1065 I0. J-0.25
G1 Y-3.4135
G2 X3.1136 Y-3.6635 I-0.25 J0.
G1 X0.1214
G2 X-0.1286 Y-3.4135 I0. J0.25
G1 Y-0.1065
G2 X0.1214 Y0.1435 I0.25 J0.
G1 X1.6175
G3 X1.6675 Y0.1935 I0. J0.05 F5.
G1 Y0.2435
G19 G3 Y0.2935 Z-1.6729 J0. K0.05
G0 Z0.6
G17
G28 G91 Z0.
G90

[bostosh]

Run the Gcode thru a G-code visualizer CAMotics

[109jb]

G28 G91 Z0.

What location is stored for the G28 parameter?

[eman5oh]

G28 G91 Z0.

What location is stored for the G28 parameter?

What he said, the G28 is a return to home command.

[AVRnj]

G28 G91 Z0.

What location is stored for the G28 parameter?

Thanks!

I don't have any homing setup becasue I don't have limit switches yet. So my G28 is 0,0,0

I guess I should remove that whole line then? I dont' see what I would need the G91 for at that point in the program. So is it best to just remove the whole line?

[daniellyall]

You can home in places, what just means park the machine somewhere where it wont crash with the Z at the top of it's travel and hit the home button, problem solved