Question about automated Z0 approach

[extrapilot]

Hi

I like the screenset very much- and find some of it intuitive even for more complex things.

But- Im having a difficult time understanding what should be a simple process for a Z=0 automated touchoff process. I cant find a method which makes sense to me, given a hobby mill, with low confidence in precise home switch trips, and with NRH R8 holders that don’t make a tool table worth anything.

At present, using the default screen and a few buttons/scripts- this is how I approach automated Z0.
- Set any cutter/master tool to the cut Z0 via a shim, and manually set the WCz to 0
- Position the mill over the touchpad, which can be at any Z height within reach of the mill
- Run a script which looks for the touch signal, halt motion, and then store that Z offset value as a variable

From then on, until my cut Z0 changes (i.e. a flip), or I need to move my touch plate, I only need to change tools, position the mill over the TP, and execute a script. That script looks for the touchoff signal, updates the WCz with the offset bias previous stored, and returns to the MCxyz at that script's init.

That way, I get a consistent Z0 value for a tool, and I don’t have to deal with TLOs, tables, a fixed location for the TP, or concerns about negative vs positive offsets, etc.

Is there a way to accomplish this in this Screenset? Perhaps it is right in front of me (i.e. some variation of master tool Z), but it seems like the only way to do this would be to manually alter the gauge block height for each setup, and (presumably) to manually setup the XY position for the TP. And that seems a source of error-

Regards

[DaveCVI]

Hi,

...
That way, I get a consistent Z0 value for a tool, and I don’t have to deal with TLOs, tables, a fixed location for the TP, or concerns about negative vs positive offsets, etc.

That approach has you essentially resetting the WC Z offset (the delta between MC Z0 and WC Z0) each time you change tools.
MSM is not designed to facilitate that approach because in industry, the WC Z offset is not generally considered to be a function of the tool that is mounted. Rather, the WCZ offset it is an attribute of where within the work envelope of the machine you have decided to place WC Z0 - which is independent of the tool in use. In contrast, Tool Length Offsets are used to allow gcode to be written without knowing the physical length of the tools that will be used until the time that that gcode is actually run.

The one community I'm aware of where resetting WCZ Offset per tool is (somewhat) common are hobby CNC users usually running wood routers.

There's a trade off - While resetting WC Z0 at each tool change may let you ignore "TLOs, tables, a fixed location for the TP, or concerns about negative vs positive offsets, etc.", it also means that you can not get the advantages which those features enable.
MSM was designed to support common industry mill operation practices with Mach3.

Effective use of MSM pretty much requires a referenced machine (and thus decently accurate home switches).
MSM will happily measure a tool as part of a tool change and update the tool tables with the measured tool length and calculate the appropriate TLO value for the tool table. MSM supports the use of NRH holders and tool tables (since the tool is measures after it is mounted in the spindle). Generally, there is no need for this ability in industry machines (since they typically have all CAT40 holders which are inherently RH), but is is quite handy for R8 spindles that may be using collets etc.

Honestly, if you prefer resetting WCZ0 for each tool, and that works fine for your needs, MSM is probably not a good fit to your preferred work flows.

Dave