What is creating "fixture" in output file?

[freman]

I find a "fixture" operation which is hitting the Z limit switch. I could always just edit this out by hand but I'd like to know what it is about and maybe there is some other setting I need to adjust.

My path and all clearance heights are a 2mm, and that's what I intended. The 3D view does not show anything above that level. Also inspecting Gcode does not go higher. The surrounding text is coming from the grbl post-processor but is processing something from FreeCAD.

Code: Select all

(Exported by FreeCAD)
(Post Processor: grbl_post)
(Output Time:2019-06-21 19:47:48.401952)
(begin preamble)
G17 G90
G21
(begin operation: Fixture)
(Path: Fixture)
G54
G0 Z3.553
(finish operation: Fixture)
(begin operation: T9: 6mm ball-end mill)

OS: Linux (LXDE/LXDE)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.16988 (Git)
Build type: Unknown
Branch: master
Hash: ff7975291d33a88e6a8282b88a62dbcbcc01ba2b
Python version: 2.7.15
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedKingdom (en_GB)


Can anyone tell me where this Z3.55 is set?

TIA.

[iksrogerg]

Hi,

I have a similar problem. My controller ignores the "G53" gcode and understands only the "G0 xxx" which is an unintended quick move to the stock surface in my case.
As far as I understood from "PathPost.py" the height comes from :

e.g. line 319 "c2 = Path.Command("G0 Z" + str(job.Stock.Shape.BoundBox.ZMax))
that means from the Zmax coordinate from the stock.

I replaced the line by "c2 = Path.Command("G21")

Very quick and dirty, but fixes my problem.

Maybe you can adapt the Zmax.

Regards
Klaus

[freman]

Thanks, I will look into that. However, since I was tight for space, I think I had set zero to the stock surface with bound box at zero. So job.Stock.Shape.BoundBox.ZMax = 0

I will look back if still have a copy of that.