help needed with this g code

[Anonymous]

hi. I am using fusion 360 to write the g code for a part i wish to make. the ,illing machine uses mach 3 to read the code and produce the work. but when i download the fusion 360 code to mach and start the work process the cutting tool just drills into the work surface and i need to stop the run before it drills into the machine bed. what is going wrong and what is the fix. here is the first

 cut g code.

(WHEEL SLOT CUT FRONT FACE WHEEL)

(T2 D=2.381 CR=0. - ZMIN=-0.5 - FLAT END MILL)

G90 G94 G91.1 G40 G49 G17

G21

G28 G91 Z0.

G90

(2D POCKET3)

M5

M9

T2 M6

S22056 M3

G54

M8

G0 X7.486 Y5.271

G43 Z15. H2

Z5.

G1 Z2.738 F251.

S11056

X7.493 Y5.274 Z2.678 F351.

X7.514 Y5.283 Z2.621

X7.548 Y5.297 Z2.573

X7.591 Y5.315 Z2.535

X7.643 Y5.336 Z2.51

X7.698 Y5.358 Z2.5

X9.949 Y6.28 Z2.415

G3 X8.96 Y7.646 Z2.356 R11.684

G1 X6.485 Y4.861 Z2.226

X9.949 Y6.28 Z2.095

G3 X8.96 Y7.646 Z2.036 R11.684

G1 X6.485 Y4.861 Z1.906

X9.949 Y6.28 Z1.776

G3 X8.96 Y7.646 Z1.717 R11.684

G1 X6.485 Y4.861 Z1.587

X9.949 Y6.28 Z1.456

G3 X8.96 Y7.646 Z1.397 R11.684

G1 X6.485 Y4.861 Z1.267

X9.949 Y6.28 Z1.136

G3 X8.96 Y7.646 Z1.077 R11.684

G1 X6.485 Y4.861 Z0.947

X9.949 Y6.28 Z0.817

G3 X8.96 Y7.646 Z0.758 R11.684

G1 X6.485 Y4.861 Z0.628

X9.949 Y6.28 Z0.497

G3 X8.96 Y7.646 Z0.438 R11.684

G1 X6.485 Y4.861 Z0.308

X9.949 Y6.28 Z0.177

G3 X8.96 Y7.646 Z0.118 R11.684

G1 X6.485 Y4.861 Z-0.012

X9.949 Y6.28 Z-0.143

G3 X8.96 Y7.646 Z-0.202 R11.684

G1 X6.485 Y4.861 Z-0.332

X9.949 Y6.28 Z-0.462

G3 X9.339 Y7.17 Z-0.5 R11.684

S22056

X8.96 Y7.646 R11.684

G1 X6.485 Y4.861

X9.949 Y6.28

G3 X9.339 Y7.17 R11.684

X9.247 Y7.244 Z-0.468 R0.238 F2051.

X9.163 Y7.264 Z-0.381 R0.238

X9.131 Z-0.262 R0.238

G0 Z15.

M9

G28 G91 Z0.

G28 X0. Y0.

M30

[HughesTooling]

This comes up all the time, people buy a cheep mill with mach3, it has no limit switches so has no home position. When the line G28 G91 z0.0 is executed the machine should go to the machine home but as you haven't homed the machine it goes to the work Z0. On the post dialog look through the properties for a line useG28 and set it to no, make sure the Z0. on the machine and in the CAM match. Also go to the CAM forum and do a search and you'll find some other workarounds for your machine.

Mark

[jim_g]

I use Mach3 mill also and I had to deable the use of G28 and also I had to remove the G43 tool offset. Cutting those two items out and the code run ok. G28 can be turned off when you post the code and it stays off the next time you post, but I can not find a way to stop G43 and I have to edit it out on each post.

Hoope this helps