How do I set the tool table?

I haven't used the lathe for months. Primarily because after changing a tool it takes me a couple of days to get the tool table working properly. The procedure have been to use the Touch off function in Axis to get me somewhat Close. Then go in and fine tune it by calculating offsets to whatever was there. But this can easily take many hours With 8 Tools!

So I thought I would try overriding tool 1 to X=0, Z=0 as suggested: forum.linuxcnc.org/26-turning/26991-conv...-250b?start=40#74100 . I did that by editing the tool table, then saving it.

Then I brought tool 1 to the face of my part and did Touch off G54 Z=0. Then X to the periphery of a 12.5mm rod and Touch off G54 X=12.5.
After that did a M6T3G43 to bring in a threading tool. Jogged it to point at the face of my part and Touch off Tool table Z=0. Then touched the periphery of my part and entered 12.5.
After this the DRO's showed silly numbers! I include a screenshot in case there is a Clue in there that I don't know I should mention. Other than tool 1 and 3 the tool table shows "old" numbers not touched in this attempt.

It may be a clue that the numbers seems pretty Close to the offset from the home position.

I really hope I can get somewhere With this. As it is the lathe just sits there occupying space. After trying to do something with it I am close to needing psycotherapy.

Einar wrote: After that did a M6T3G43 to bring in a threading tool. Jogged it to point at the face of my part and Touch off Tool table Z=0. Then touched the periphery of my part and entered 12.5.
After this the DRO's showed silly numbers!

That's odd.

You _might_ need another G43 after the touch-off. (You do with Touchy).

I assume that the DRO is set to show work coordinates?

You need to enter a diameter if the lathe is in Diameter mode, and a Radius if the lathe is in Radius mode (both when touching off T1 into G54 and when touching-off the tool table.)

G10 L1 P1 X0 Z0 will set the tool-1 tool-table to zero, that's easier than editing the tool table.

I tried adding G43 after Touch off. It did not seem to make any difference.
The lathe is in diameter mode. I find that most intuitive.

It seems to me that what goes into the tool table when I Touch off Tool table is an offset from machine home position.

Could it be that my version of LinuxCNC (2.6.0~pre) have a bug that have been driving me mad?
I do not know how to find and traverse the version list to see if this is a bug that have been fixed.
And I never found this to be working as expected.
It seems to me very few are using LinuxCNC for a lathe, so lathe specific bugs may go unnoticed for a while I think.

Just now I have too many other items (cars, house, ...) that needs attention to start a new install.
But if it is a known bug I will at least just stop trying until I can do a new install.

No, I have been using LinuxCNC with a lathe since 2.4 and it has always worked as-expected.

Later versions do at least have separate buttons for tool touch-off and coordinate-system touch-off.

When you touch-off, whether to G54 or the tool-table, the DRO should show the number you typed.

One thing that might change this is if you have "tool touch-off to fixture" set in the machine menu.

Also check that you are displaying commanded position and relative position in the View menu, just to keep things simple.

andypugh wrote: One thing that might change this is if you have "tool touch-off to fixture" set in the machine menu.

And that is what it was set to!
Now corrected and everything works just as expected.
Thank you!!!!!

Sounds like my problem!
If my machine has no limit or home switches and no tool changer why do we need to home the axis?
If the stock, part, toolpaths, retracts, etc. are all within the machine envelope soft limits are not required, right? If I zero my Z and set the X by touching off to part I should not need any tool length offsets, correct? I am using a manual quick change tool post.
what would a tool length offset be relative to??? as the tip of the tool is an arbitrary point in space. I do understand it could be relative to a different tool tip after this new tool is touched off to the same surfaces as the original tool.
A couple of versions back I would do just this! touch off the tool and start making parts now it's just mathematical insanity where nothing is reproducible. even the inputs for touchoff, and tool touchoff seem to randomly prefer radius or diameter. Can someone please point me to a current startup work flow for turning?