Tool touch off from fixture need help

MarkD2 wrote:

My problem is that I do not understand the touch off to fixture and subsequent touch off to work to set G54.

I get a bit confused by touch-off to fixture and work myself

Unless you have a tool length probe then I don't think you would ever use touch-off to fixture.

So, with your reference tool loaded, make sure the tool offsets are zero, and male a test cut on diameter. Measure the diameter and set your diameter with goordinate system touch-off. Your DRO should now read diameter correctly.
Make a facing cut, and set G54 Z=0
Now change tools, make another test-cut on diameter and this time use _tool_ touch off to store the tool length relative to the reference tool.
At this point I typically _don't_ use test cuts for Z, instead I move the tool close to the faced-off reference face from earlier, and then jog away until a 6mm dowel just slips between the work and the tool. Then set the tool-touch-off to +6 mm.

Note that you won't necessarily see the DRO update without a G43 in MDI. (touchy doesn't update, I can't recall if Axis does)

Now you can happily change G54 Z using any tool. (I tend to jog, set zero, and then make a facing cut at zero)
You should avoid changing G54 X ever again, but if you do change it by accident then you should be able to restore the value with the correct G10 command in the MDI window. Consider making a note of the number.
This all assumes that you have accurate home switches. (I have resolvers acting as 24-bit absolute encoders, so my homes are spot-on). If you don't have good home switches then you might need to make a test cut every time. If your tool offsets are good then you can make the test cut with any tool.