gmoccapy z height after hitting start

For some reason the tool is always way above the work. Every axis was zero, it homed Z, came down and its very high up. If i rezero Z again, it works as it should. Ideas?

If you zero without G43 'TLO Z' will be zero and once you activate it then the controller will lift the spindle up by the tool length offset (TLO Z) which seems to be set to 1.5 (inches probably).

I did have a 1.5" offset added to tool 12, but took it off. Had the same issue still.

Take a screenshot of the whole screen so we can see what G/M codes are active also if this happens when running gcode then please attach that as well. We're just poking around in the dark like this.

Similar issue. Home made router with manual tool change, linuxcnc newbie. machine has been working successfully for 2 years.
About a month ago, the tool started cutting deeper than it should. Initially blamed a mechanical problem and performed many tests.
Today I discovered TLO (as I mentioned, a CNC newbie) and found the -1mm offset was in the tool.tbl file. Had ignored this file up to this point.


The INI file has not changed in the last year. Why had this not been a problem before? I do try to keep linuxcnc up to date, so an update may have triggered it.

The INI file has not changed in the last year. Why had this not been a problem before? I do try to keep linuxcnc up to date, so an update may have triggered it.

There is no need to change the ini file to get different behavior like this.
TLO can be activated/deactivated through Gcode (G43/G49)
Tooloffsets can be changed through Gcode (G10 L1)


Sounds like you are missing some fundamental concepts of CNC control. Without a sound understanding of Gcode you are bound to get affected by all kinds of pitfalls.
linuxcnc.org/docs/html/gcode/g-code.html

Understand. I use freecad to generate the gcode from 3d models. The gcode header seems to be the same. I compared a file that was causing the issue with one from 2 years ago. Only the date and tool size was different until after the G43 H2 line which prompts for inserting tool 2.
This is routine as I always create a different path job for each tool so they are always tool 2 ( 1 being the default tool).
Why did the behaviour change?

tool size was different until after the G43 H2 line which prompts for inserting tool 2.

That command does NOT prompt for 'inserting tool 2', that command activates TLO with offset values defined in the tool table for tool #2.

If you are not using TLO in linuxcnc anyway then I would recommend setting freecad up so it does not output GCODE that activates TLO. This way there are no surprises whatever offset values you have in your tooltable.

Why did the behaviour change?

Probably not the answer you want but most likely due to operator error.