Indexed Cut requires Z-Axis offset

Kiri:Moto CAM
1

Hello,
Doing a 4th Axis/index cut and I’m trying to understand why my first z-axis position in the Animate pane is -17.01. This causes my bit to dive into the stock (wasn’t paying attention first time). My current work-around is to add a -18 zOffset. Is this work-around expected?

Thanks,

Anthony

Screenshot 2025-04-05 at 8.05.06 PM
Screenshot 2025-04-05 at 8.05.06 PM1920×1284 121 KB

2

Hi Anthony,

I can’t tell from your screenshot where your origin is. Can you email your workspace .kmz (files → export) to [ sa at grid dot space ] ? I can take a look

1 Like
3

Got the workspace. When I import it and slice/preview/animate, the first cut is at a proper depth. iow, I don’t see what you’re seeing. Try a couple of things:

a) import the workspace you sent in a private browsing tab
b) enable first z max and/or force z max and see if that helps

Observations. In all my indexed work, the Z origin is center. iow, z=0 is on the X axis. Are you planning to do indexed milling? if not, then non-indexed mode will be faster and probably have fewer bugs. if you can do this as a double-sided job, there are “flip” and “registration” provisions for non-indexed cam.

4

I definitely want to use the index feature so I can mill each side and then a lathe operation.

I’ll give your options a shot. Even with the zOffset, the generated g-code still has the negative z-index.

G21
G90
M6 T7
G0 X8.1081 Y6.5542 F6000
G0 Z-16.9992 A0.0 F300
G1 Z-20.0080 F250
G1 X-16.9081 F800
...
5

Just following up:

  • Tried Incognito and completely different browser (I don’t use Safari) - both gave me the same behavior.
  • tried first and force zMax everywhere. same behavior:-(
  • my -18 zOffset fixes the simulation but when I export the g-code, it still has a negative values in it.

Glass is half full, I am much better at inspecting my g-code for anomolies now, but still stuck here.

6

uncheck origin top and all your cuts will be positive Z. I feel like I’m still missing the plot.

Screenshot 2025-04-06 at 12.07.15 PM
Screenshot 2025-04-06 at 12.07.15 PM1920×1212 179 KB

7

uncheck origin top and all your cuts will be positive Z.

That places my Origin in the middle of my stock which would require me zeroing XYZ without my stock mounted.

I’ll start playing with the code/make a PR. I’m not sure why others aren’t having more issues with indexed cuts, but I’m seeing some inconsistencies (like offset Z effecting the Animate Panel, but not the generated G-Code)

Thanks for the help. I’ll dive in further:-)

8

On Carvera when homing it uses a known offset and Z = 0 is on the X axis. I have not worked with other indexed machines. Indexed milling is the newest and buggiest thing in CNC mode. I have not had a lot of time for testing other than roughing and lathe.