Fusion360 toolpath problems

ive been making some hole plugs for work. made many many many of them. now all of a sudden anytime i create a toolpath in f360 first thing it does is go to the top of Z and hits limit switch. I have no idea what ive changed but its had me stumped for days. below if the first few lines of code, any help or ideas would be greatly appreciated!

(T2 D=0.25 CR=0 - ZMIN=-0.9899 - flat end mill)
G28 G91 Z0

T2 M6
S24000 M3
G0 X0.4651 Y0.4261
G1 Z-0.1 F120
X0.4648 Y0.4259 Z-0.1039
X0.464 Y0.4255 Z-0.1077
X0.4627 Y0.4247 Z-0.1113
X0.461 Y0.4236 Z-0.1147
X0.4588 Y0.4224 Z-0.1177
X0.4562 Y0.4208 Z-0.1202
X0.4533 Y0.4191 Z-0.1223
X0.4502 Y0.4173 Z-0.1238
X0.4469 Y0.4153 Z-0.1247
X0.4436 Y0.4133 Z-0.125
G3 X0.3335 Y0.3309 I0.3252 J-0.5491
G1 X0.3303 Y0.3277
X0.3257 Y0.3239
X0.3212 Y0.3199
X0.317 Y0.3156
X0.313 Y0.3112

1 Like

The first Z move is
“G0 X0.4651 Y0.4261

If you jog to where you think XYZ zero should be, and it isn’t showing values in the DRO that are close to zero, you’re zero isn’t set properly for whatever reason, and would readily explain why that first move wings you off into someplace you don’t expect.


You probably don’t have a g28 set. Set one, or disable G28 retracts.


@neilferreri’s comment made me remember I once had a similar problem where for some reason my GRBL has lost its G28 reference, this may have happened to you if nothing else changed in your workflow.

Quick fix: home the machine, send “G28.1” (without the quotes) using the MDI.

If as I suspect you are using the Carbide3d post.processor in Fusion, you don’t have the option to disable G28 retracts (at least the version I have installed doesn’t). You can (and should) reset G28 using the G28.1 command as decribed above, you could also jump ship and install @neilferreri’s most excellent post processor for the Shapeoko, and then you’ll have the ability to customize whether you want G28 retracts or not (as well as other options)


You guys are awesome, that fixed it! Thanks for the quick response!


What are g28 retracts typically useful for, clearing work holding?

I think that’s the intent, yes.

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