> From: N [mailto:nicklas.karlsso...@gmail.com] > On Mon, 31 Aug 2020 14:42:12 -0700 > "John Dammeyer" <jo...@autoartisans.com> wrote: > > > I have one of these. > > Fowler 54-575-600 Electronic Edge Finder with Cylindrical Tip, 0.200" > > Stylus, 1/2" Shank > > Thinking about it there is no need to probe height of part so no need for z > direction, just have to place tool presetter on known > height compared to machine vise. > For my CNC router I use a small piece of single sided fibreglass PC board with a wire for a clip lead. This runs to the Break Out Board. I clip a ground lead to the tool bit held in the router collet. Since I can measure the thickness of the PC board with a micrometer I know that if it's sitting on the top of the work or vise jaws or CNC router bed that when the tool bit contacts it and connects that input to ground that I'm a known distance from whatever the plate is sitting on.
The macro I modified for MACH3 brings the tool bit down and on contact moves back up and logs the Z zero position. I then disconnect the clip lead and remove the plate. Since the router doesn't have a repeatable tool holder this has worked out really well each time I replace the tool bit. With the Mill with the TT holders things have to be different. It's easy enough to use the same approach though. All that's needed is one tool/probe in the holder that has a known length. That once can be then moved down to a PC board plate like the one I use for the router to establish current Z axis 0. At this point each TT tool holder with tool can be touched off the same place. Then taking into account the original probe value the tool table can be updated. As long as the tools aren't changed in their holders only the Z point has to be recalibrated if things are changed. I have not yet written any sort of tool touch of macros or functions in LinuxCNC. No idea where to start with that. John _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
