This readme file is intended to be repository for comments and information regarding the related INI and HAL files, in order to avoid cluttering up those files with comments.  They are modified versions of pncconf-generated ones from 2.8.2.  Documentation for 2.8.2 is at ( http://linuxcnc.org/docs/2.8/pdf ).

last updated 2-8-22

machine information
-------------------

-cnc table with 6' rails for 5' x 5' cutting area
-built with Plamsa Bot carriage plate kit and BOM from ShopDroids CNC (user tulsaturbo on cnczone.com forum)
-4X NEMA 23 steppers (1 X, 2 Y, 1 Z) with 1.8 degree step angle driven by Gecko G540 (10 microstep resolution)
-Mesa 5i25 card inside Dell Optiplex 980 with core i5-650 3.2 Ghz
-MDFLY MOL-DB2505 breakout board in between 5i25 and G540 to break out pins 18 (GND) and 14 (PWM) for laser
-laser is Kale CNC 1400 mW 445 nm module (use 1" focus dist. from bottom of module to workpiece surface)
-turning X, Y1, or Z motor CW when looking at shaft end (+ dir by right-hand rule) moves in positive linear direction
-turning Y2 motor (which is on right side of machine) CW moves it in the negative Y direction
-therefore, scale for Y2 joint needs to be negative
-Y2 motor is connected to 4th (A axis) driver of G540

INI file
--------

-keep [EMC]VERSION at 1.1 to avoid config updater script prompt (see 8.2.2.1 in documentation)
-linear velocities are in in./s (5 IPS = 300 IPM should be good max velocity)
-in both [KINS] and [TRAJ] section, "coordinates" variable specified as XYZY (was XYYZ out of pncconf) for the following joint assignments:

X 		= 	joint 0
Y1 (left) 	= 	joint 1
Z 		= 	joint 2
Y2 (right)	= 	joint 3 

-scale factors = (steps/rev) x (microsteps/step) / (PD * pi)
-X and Y gears are 0.75" PD --> 848.826363 microsteps/in.
-make sure scale for joint 3 (Y2) is negative (see comment in machine information section above)
-Z gear is 0.625" PD --> 1018.591636 microsteps/in.
-kept defaults from pncconf for G540 DIRSETUP, DIRHOLD, STEPLEN, AND STEPSPACE
-values for above from 2.5.3 config were:

DIRSETUP   =              2000
DIRHOLD    =              2000
STEPLEN    =              4000
STEPSPACE  =              4000

-added HOME_SEQUENCE values for each [JOINT_#] section:

joint 0 (X) --> 0
joint 1 (Y1) --> -2
joint 2 (Z) --> 1
joint 3 (Y2) --> -2

-got rid of "kinstype=BOTH" in [KINS] section
-commented out everything in [HAL] section except main HAL file
-changed INTRO_TIME to 3 in [DISPLAY]
-using 10,000 rpm as 100% laser power in [SPINDLE_0] section 

HAL file
--------

-deleted pdm_frequency line in first section (not using pdm)
-stepgen assignments:
 
00 X motor
01 Y1 motor
02 Z motor
03 Y2 motor
04 chargepump

-axed the following sections: toolchange, coolant, probe, HALUI, and home/limit switch (home/limit switch was a sub-section in each axis/joint section)
-PID and closedloop stepper stuff needs to stay even if steppers are open-loop (no encoder)
-had to fix position-scale and velocity-cmd values in stepgen.04 section for chargepump to get 10 kHz freqency
-step_type 2 in that same section is quadrature-style output and forces 50% duty cycle (regardless of step length and step space values being less than T/2)

# end of README file