Probing and automatic tool length measurements

Oh, sorry for publishing this before being satisfactorily complete. I have spent many months just to get it to work and I am hoping that others can get going a lot faster by having a reasonably working example to look at.
IMHO, at least TLO probing should be part of the basic setup. And 3D probing sure is nice! And together - wow!

Thanks,
/Chris

A couple of changes have been made to improve z precision from 0.15 mm to 0.03 mm with my TLO measurement mushroom.

First, the manual_change.ngc had these last three rows added to make a second probe move at slower speed:
Then the *.ini was modified with new PROBEFEED:
Thanks,
/Chris

I'm planning to implement this automatic tool length measurement on my machine and as far as I tested in simulation I don't understand function of Reference Tool button?

Also there I have question about procedure to touch-off Z from workpiece with first tool which I usually already have in spindle before running any code, should I manually enter T1 M6 to let machine know that first tool is already present and it will be used as "reference tool"?

Hi Tommy!
Yes, I suggest manually entering T6 M1 before running the program. This will cause the machine to go to the tool change position. There, you should go to the tool change tab and make sure the reference tool button is active and the hit the probe button. This initiates the probing which should result in the reference tool length being updated. You can then proceed to touch off against your workpiece. I use my 3D probe for this, but that is not a requirement. Any tool, dowel or custom designed tip suitable for touching off can be used. When done, you can start executing your code, which will take you to the tool change dialog again. This time, be sure to uncheck the reference tool button and proceed. I am not sure what will happen if your code specifies tool #1 again. Maybe it skips the touchoff and just starts executing. Should work either way, I suppose, but I have not actually tried that.
The purpose of using a reference tool, is that any other tool will get a tool length offset (TLO in the readout) with a non-zero value in relation to this.
Hence, I have found (the hard way, of course...), you want to start every operation with M2 and G49 before T6 M1 to make sure any pending settings and active tool length offsets are canceled. That is what I was planning to use the reset button for.

Good luck and please report back with your findings!
/Chris

My findings after implementation to config of my machine, so procedure I was trying is:

- Fresh start of LCNC (reference and current Z lengths are both zero)
- execute T1M6
- insert tool #1
- activate Reference tool button
- click Change complete
- after tool was measured Current Z length is still zero, Reference Z length is negative number (I guess probed distance from absolute Z0) then I touch off for all three axis on workpiece
(no g-code was executed)
- execute G49
- execute T2M6
- insert tool #2
- deactivate Reference tool button
- click Change complete
- after tool was measured, value in Current Z length is way way to big to be used for tool length!

Did I missed something?

Yes, executing G49 in the middle will clear the tool offset you just measured and set, so skip that and you should be ok.

/Chris

Hi, can someone help me how to install this extesion auto tool measurement. I am novice at linuxcnc.

Thx Martin

Hi,
Thank you for your fast answer. But can you tell me how to install it.. Whitch file copy/put to.... I am distracted. I sucessfuly install probe screen to my Linux cnc but i dont know how to install this screen ,, auto tool measurement,,. Sorry if my questions are stupid.

Thanks Martin

Have a look here, I use this touchoff and tool measurement on my machine:

forum.linuxcnc.org/forum/10-advanced-con...h-touch-off?start=30

Cheers