Four + axis

[Ray Henry <rehenry-at-up.net>]

Where we are with Four + axis

I've got a stepper on the fourth axis here and it works okay for manual
rotary moves.  I don't know how it will work with servo.

There is no provision in the current rs274ngc interpreter for a, b, c
words.  Tom Kramer indicated that he will have an interpreter for up to six
axis soon.  Fred pointed out the the motion planning files need work before
we can run a fully integrated four or five axis machine.  He thought it
would a few months before that stuff is ready.

I put tkemc4 on hold while trying to figure out why TclTk is doing the
goofy stuff that Jon E. reports.  

For now, when you run 4+ the gui to use is yemc.  As shipped, yemc is very
tall and requires some work in order to show successfully on 640 or 800
resolution screens. Since it is intended for more than three axis it will
adjust itself when it is started to the number of axis defined in the .ini
file.

What I did to make yemc work for me is to first change its appearance.  The
real file that does the appearance work is the Yemc that resides in
/usr/X11/lib/X11/app-defaults. Don't be confused by the file of the same
name in the emc directory. Editing the emc/YEmc file will not change the
appearance of your yemc unless you packup emc after making the changes and
then reinstall the whole thing from your packup. Or overwrite the
/usr/X11/lib/X11/app-defaults file of the same name. 

The following changes are what I made for the "real" YEmc file.

----------------------------------------------------------------------------
-----

*font: -adobe-helvetica-bold-r-normal--10-*-*-*-*-*-*-1
*menu*font: -adobe-helvetica-medium-r-normal--10-*-*-*-*-*-*-1
*fileEditorText*font: -adobe-helvetica-medium-r-normal--10-*-*-*-*-*-*-1
*toolTableText*font: -adobe-helvetica-medium-r-normal--10-*-*-*-*-*-*-1
*varFileText*font: -adobe-helvetica-medium-r-normal--10-*-*-*-*-*-*-1
*helpXemcText*font: -adobe-helvetica-medium-r-normal--10-*-*-*-*-*-*-1
*posLabel0.font: -adobe-courier-bold-r-normal--32-*-*-*-*-*-*-1

----------------------------------------------------------------------------
------

These lines are spread throughout the rather long file and only the font
size is reduced. 

Next edit your .ini file to reflect 4+ axis and add the initialization
stuff for the extras.  The type of axis I used is ANGULAR.  The soft limits
are in degrees.  Select yemc for display and start it up.

Axis displays will not work for 4+ unless you change <settings> to the
<joint> rather than world system. I'll drop a jpg on linuxcnc.org that
shows a screen shot of a four axis version that will fit on an 800
resolution screen.  It shows, yemc displaying a rotary fourth axis, while
running the program cds.ngc. 

Ray