Lathe - tool offset in Y does not work

Hello,
I have a CNC mill. For a small project, I would like to use it as a lathe. Therefore created a new configuration, set LATHE=TRUE in the AXIS section of the ini file. My setup is as follows:
- the Z & X-axes are preserved,
- the workpiece is mounted in the spindle,
- there are 3 lathe tools mounted on the mill table in different Y distances - by moving the Y-axis I would like to change tools.

Then I set up 3 tools in my tool table - with various X, Y a Z offsets. In the program, I expect that issuing tool change followed by G43 causes the machine to apply these offsets in the next machine move. It works well for X and Z, but Y-axis seems to be ignored by the system. However, when I open the DRO tab in AXIS, I can see Y TLO applied. But the physical movement does not correspond with the Y offset - the machine does not move in the Y direction. The Y-axis works I can jog with no problems. It is also shown on DRO screen. Just the Y-axis offset is not applied.

What have I misconfigured? How can I fix it?

Please post your config files. and what version of linuxcnc are you using?

Chris

Lathes use only X and Z axis, so to use Y axis for changing tools my gues is it would have to be set as a toolchanger by using M codes or remap. Chris is much more experienced for that, so i will shut up now.

Thank you guys for a quick response. I attach my configuration. Just for illustration for what my setup looks like I a video from a first test of the setup (using only a single tool): photos.app.goo.gl/3KPXwsMZFytU6hhZ9

yaqwsx wrote: Thank you guys for a quick response. I attach my configuration. Just for illustration for what my setup looks like I a video from a first test of the setup (using only a single tool): photos.app.goo.gl/3KPXwsMZFytU6hhZ9

Very nice, thank you.

I don't think you miss configured.
I think that the programmers of AXIS assumed lathes don't ever have a Y axis.

In fact i am wondering how you homed the Y axis?

Chris

In the top menu there is option to home Y axis. Also, home all homes everything.

How can AXIS change behavior of the G-code intereprer? I thought they are independent and G43 should behave the same... I have to check if my Mill configuration can do offsets in the Y direction.

I do agree that seems weird.
I didn't search to see how far the LATHE=True switch manifests.

what version of linuxcnc?
do you program a move in y after applying the offset?

Today I solved the problem. It was my own stupidity.

When G43 is called, the interpreter will apply the tool offset not in the next move but it applies the offset by components - when the individual axes move. Therefore, since my program does not contain any Y-axis movements, the correction was never applied. Instead, once G43 was called, the axis immediately changed its position to -offset.

To fix it, I modified my post-processor to produce tool change like this: