Working out a tool changer method for mill

Is the rack connected to the X/Y axes, or controlled by separate actuators?

If the rack is somewhere that can be reached with normal axis moves, then you could remap M6 to a g-code sub, there is an example of this config here:
git.linuxcnc.org/gitweb?p=linuxcnc.git;a...89d8c917be31f9a1efa6
And remapping docs here:
www.linuxcnc.org/docview/devel/html/remap/structure.html
You do need to run the "master" ( ie development ) branch of LinuxCNC to get this capability, but that is available as an installable package from builbot.linuxcnc.org

Otherwise, more detail needed..

garymcrobertpdx wrote:

Thanks for the info
I looked the examples over this appears not to be a simple matter and I have yet to figure out
how this method works.

It's relatively straightforward, I think.

This line in the INI:
REMAP=M6 modalgroup=6 prolog=change_prolog ngc=rack_change epilog=change_epilog

Means that any "M6" command in the G-code calls the G-code subroutine called "rack_change.ngc"
That G-code uses that fact that in the 2.6 version there are predefined parameters called things like #<_tool_selected> which tell the G-code which tool is needed.
(There are lots of these, the most useful being things like #<_x> which returns the current X-position. )

It also calls the routines called "change_prolog" before the tool change, and "change_epilog" after the tool change. The first checks that the tool number is valid and raises an error if not, the second actually tells LinuxCNC that the tool change has happened. These routines already exist, so you only need to copy the rack_change.ngc code (and modify it to suit your system)

There are a few other settings in the example INI file, to load a GladeVCP control panel for example. However, I think all the hard work has been done. You could try installing 2.6 from the buildbot and having a play around with that simulated tool changer configuration (it's a sim config, so won't actually move hardware)

garymcrobertpdx wrote:

Easy if you know the Linux OS otherwise a bit of a maze
Went to buildbot.linuxcnc.org/ read the info
To use these packages on your computer, put one of these stanzas in your /etc/apt/sources.list.d/linuxcnc-buildbot.list:
Found the directory etc/apt/sources.list.d and I see a document emc2.list there it looks similar

Well, the first semi-problem is that we changed the name. It is probably cleanest to update to the first "linuxCNC" rather than "EMC2" version.
That means LinuxCNC version 2.5.
wiki.linuxcnc.org/cgi-bin/wiki.pl?UpdatingTo2.5

Attempted to create a document linuxcnc-buildbot.list: to place the stanzas
deb buildbot.linuxcnc.org/ hardy master-rt
deb-src buildbot.linuxcnc.org/ hardy master-rt
into but the OS will not let me.

Ah, yes, you need root privileges. if you type
sudo gedit
at the command line then you get a version of gedit with root privileges.

garymcrobertpdx wrote:

how do I know if 2.6 is installed?

If you start a config, the splash-screen has the version number.

(You might as well start the sim/remap/rack_toolchange config)

By the way: You might have lost your existing configs from the startup selection dialog. The solution is to rename ~/emc2 to ~/linuxcnc