New Manual NC Action "Z_AXIS_OFFSET"

[Ksdmg]

Is your feature request related to a problem? Please describe.
It's annoying and time consuming to measure tool lengths manually with the calibration card. I'm looking for a neat way to measure tool length and calibrate them easily.

Describe the solution you'd like
My idea is to use something like this: https://www.sorotec.de/shop/Werkzeuglaengensensor-Sorotec-8mm.html and connect it with a LED. Once the Z is lowered to the point you need, the switch closes and the LED lights up. Using the knowledge we have of the tool length sensor, it might be possible to add a manual NC command to Fusion to offset the Z by this value. So for example, I'm setting my origin to:
X:150
Y:30
Z:68
Manual NC Action "Z_AXIS_OFFSET -8" is being added and converts it to:
X:150
Y:30
Z:60

This could be extended for a toolchange. If my first operation is an adaptive clean with a tool that has a 50mm length, I'm calibrating the Z with "Z_AXIS_OFFSET -8". Then I'm changing over to a tool with 40mm length and I would add "Z_AXIS_OFFSET -18".

[nunorvoliveira]

I'm not sure if I'm understanding your point...

The way the post-processor works, is by creating a CNC file with all the instructions needed to perform a machining.

It's not possible to have the CNC file reading a tool measurement in the middle of the machining operation.
Also, it's not possible to read the signal or measurement of that tool probe.
This would only be possible if it was implemented by the machine itself as far as I understand.

One possibility is to create one CNC file for each tool and manually calibrate each tool with the tool probe you show. It is still a semi-manual operation as you have to manually move the tool. The only difference.is that instead of using the paper (or a feelers gauge as I do) you will me monitoring the led and then do some calculation to translate the Z coordinate to the needed value.

Anyway, if I'm not understanding something in the correct way, please just let me know.
This is a new world for me so I may be misinterpreting something...

[Ksdmg]

So I'm new to this too, but maybe this could work:
Z_AXIS_OFFSET -8 results in the following command:
https://snapmaker.github.io/Documentation/gcode/M206 -> M206 Z-8

As the M206 command can receive multiple axis, maybe the command could be "AXIS_OFFSET" and we pass in "AXIS_OFFSET Z-8" so in case you want to offset another axis it would be possible, event though I have no idea why one would want to do that.

[nunorvoliveira]

Yes, I understand the workflow.

But if we know the value "-8" in advance, we don't need a command for it. We just need to set the tool length in Fusion 360.
The problem is that this value is only known after changing to the new tool and calibrate it. And at this point there is nothing we can do as the CNC file can't read this value in real time. This would only work if the machine would implement such a measuring of the tool length and executed the M206 on its own..

We need to remember the CNC file is created on the computer, without the machine and tools... Then, when the CNC file is being executed we can't change it...

This is why I use something like this :
https://ae01.alicdn.com/kf/HTB1vcF9aBCw3KVjSZFlq6AJkFXaS/3-175-1-0MM-PCB-Corn-End-Mill-Wholesale-Mini-CNC-Router-Cutting-Bits-on-Circuit.jpg_Q90.jpg_.webp

This way, I measure the tool once, and then I can change it as much as I need and it's always spot on!

[Ksdmg]

This only works if all tools are the same length. I have a rough cutter with 4x75mm , and a 1x50mm for finishing. I would use the Zoffset action when switching cutters with different lengths.

[nunorvoliveira]

I'm going to be honest, I'm using fusion 360 personal edition that only let's me use one tool per CNC file. But it should compensate for too length when the tool changes.
Are you using the subscription version?
Or are you trying to have multiple CNC files for multiple tools and have this offset command handling the new origin automatically by offsetting it in Z?

[Ksdmg]

the latter. Like this I set the origin one time and then it's simple to say after the first roughing operation, the next tool offset z-25.

[nunorvoliveira]

Ok, now I understand 😊

This is something that seems to be possible to implement. Will have a try when I find the time.
However, it will rely on the measurement of the tool lengths in advance with the stop rings I've mentioned before as there is no way (that I know of) to interact with an external device for calibrating the tool length when running a CNC file.

Will let you know when I have something 👍