Hot wire foam cutter - mapping Z and A axes to U and V

Hi all

My hot wire machine is working, but the software I want to use (devFoam) issues X,Y, U,V parameters for G1 (four parameters on each line). I am not cutting tapered parts, so the U value is always the same as X, and V the same as Y.

I don't want to modify the gcode manually. My breakout (parallel) board is marked for X, Y, Z and A.

Can anyone help me with how to configure this?

Thanks
Garth

This is valid for configurations created with PncConf wizard, you did not give any info on the actual hardware used nor software.
Make a copy of the existing config and put it somewhere safe.
Edit the .ini file with a text editor:
display section change GEOMETRY = XYZA to XYUV
TRAJ section change COORDINATES = XYZA to XYUV
change [AXIS_Z] to [AXIS_U]
and change [AXIS_A] to [AXIS_V]
save, do not close the text editor, you might need to go back with CTRL Z
The hal file needs a bit more care
change
loadrt pid names=pid.x,pid.y,pid.z,pid.a
to
loadrt pid names=pid.x,pid.y,pid.u,pid.v
-
then
addf pid.z.do-pid-calcs servo-thread
to
addf pid.u.do-pid-calcs servo-thread
and
addf pid.a.do-pid-calcs servo-thread
to
addf pid.v.do-pid-calcs servo-thread
-
then everything under the section "AXIS Z JOINT 2" and "AXIS A JOINT 3" wherever there is z in any line, replace with u , and wherever there is a in the line replace with u .
DO not use "search and replace" feature for this, it will mess up the configuration beyond repair.

Not sure about the specifics of the foam cutter gui

But from a ini and hal side of thing you can link the two columns together.

1 copy everything tommylight said but name them x2 and y2 instead.

Now go to the ini move the joints for x2 and y2 under x and y axis sections. then delete the x2 and y2 "axis" sections

For example
X axis
Joint 1
Joint 3 (was u before)

Y axis
Joint 2
Joint 4 (was v)

Not sure if your software could only output x and y however. If it also does u and v no matter what follow tommylights suggestion

Very little difference between having 2 axis/4joints and having 4 axis/4joints as far as editing goes, so i decided to do the 4 version as it leaves the possibility of doing plane wings !

Good point, I have already started wondering about adding a weight to tension the wire, which would enable tapered cuts. So I am going to try Tommy's settings now

My ini and hal files look like this (this is the latest version of Linuxcnc - 2.9.2)

I added to the ini file but have not changed the hal file yet (I can't see where to change it)

ini

# Generated by stepconf 1.1 at Tue May 21 18:01:10 2024
# If you make changes to this file, they will be
# overwritten when you run stepconf again

[EMC]
MACHINE = garthfoam
DEBUG = 0
VERSION = 1.1

[DISPLAY]
DISPLAY = axis
EDITOR = gedit
POSITION_OFFSET = RELATIVE
POSITION_FEEDBACK = ACTUAL
ARCDIVISION = 64
GRIDS = 10mm 20mm 50mm 100mm 1in 2in 5in 10in
MAX_FEED_OVERRIDE = 1.2
MIN_SPINDLE_OVERRIDE = 0.5
MAX_SPINDLE_OVERRIDE = 1.2
DEFAULT_LINEAR_VELOCITY = 2.50
MIN_LINEAR_VELOCITY = 0
MAX_LINEAR_VELOCITY = 25.00
CYCLE_TIME = 0.100
INTRO_GRAPHIC = linuxcnc.gif
INTRO_TIME = 5
PROGRAM_PREFIX = /home/garth/linuxcnc/nc_files
INCREMENTS = 5mm 1mm .5mm .1mm .05mm .01mm .005mm
GEOMETRY = XYUV

[KINS]
JOINTS = 4
KINEMATICS = trivkins coordinates=XYUV

[FILTER]
PROGRAM_EXTENSION = .png,.gif,.jpg Greyscale Depth Image
PROGRAM_EXTENSION = .py Python Script
PROGRAM_EXTENSION = .nc,.tap G-Code File
png = image-to-gcode
gif = image-to-gcode
jpg = image-to-gcode
py = python

[TASK]
TASK = milltask
CYCLE_TIME = 0.010

[RS274NGC]
PARAMETER_FILE = linuxcnc.var

[EMCMOT]
EMCMOT = motmod
COMM_TIMEOUT = 1.0
BASE_PERIOD = 100000
SERVO_PERIOD = 1000000

[HAL]
HALFILE = garthfoam.hal
HALFILE = custom.hal
POSTGUI_HALFILE = postgui_call_list.hal

[TRAJ]
COORDINATES = X Y U V
LINEAR_UNITS = mm
ANGULAR_UNITS = degree
DEFAULT_LINEAR_VELOCITY = 2.50
MAX_LINEAR_VELOCITY = 25.00

[EMCIO]
EMCIO = io
CYCLE_TIME = 0.100
TOOL_TABLE = tool.tbl

#*** AXIS_X *******************************
[AXIS_X]
MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
MIN_LIMIT = -60000.0
MAX_LIMIT = 60000.0

[JOINT_0]
TYPE = LINEAR
HOME = 0.0
MIN_LIMIT = -60000.0
MAX_LIMIT = 60000.0
MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
STEPGEN_MAXACCEL = 937.5
SCALE = 320.0
FERROR = 1
MIN_FERROR = .25
HOME_OFFSET = 0.0
#******************************************

#*** AXIS_Y *******************************
[AXIS_Y]
MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
MIN_LIMIT = -60000.0
MAX_LIMIT = 60000.0

[JOINT_1]
TYPE = LINEAR
HOME = 0.0
MIN_LIMIT = -60000.0
MAX_LIMIT = 60000.0
MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
STEPGEN_MAXACCEL = 937.5
SCALE = 320.0
FERROR = 1
MIN_FERROR = .25
HOME_OFFSET = 0.0
#******************************************

#*** AXIS_U *******************************
[AXIS_U]
MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
MIN_LIMIT = -60000.0
MAX_LIMIT = 60000.0

[JOINT_2]
TYPE = LINEAR
HOME = 0.0
MIN_LIMIT = -60000.0
MAX_LIMIT = 60000.0
MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
STEPGEN_MAXACCEL = 937.5
SCALE = 320.0
FERROR = 1
MIN_FERROR = .25
HOME_OFFSET = 0.0
#******************************************

**********************

#*** AXIS_V *******************************
[AXIS_V]
MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
MIN_LIMIT = -60000.0
MAX_LIMIT = 60000.0

[JOINT_3]
TYPE = LINEAR
HOME = 0.0
MIN_LIMIT = -60000.0
MAX_LIMIT = 60000.0
MAX_VELOCITY = 25.0
MAX_ACCELERATION = 750.0
STEPGEN_MAXACCEL = 937.5
SCALE = 320.0
FERROR = 1
MIN_FERROR = .25
HOME_OFFSET = 0.0
#******************************************

#******************************************

hal

# Generated by stepconf 1.1 at Tue May 21 18:01:10 2024
# If you make changes to this file, they will be
# overwritten when you run stepconf again
loadrt [KINS]KINEMATICS
loadrt [EMCMOT]EMCMOT base_period_nsec=[EMCMOT]BASE_PERIOD servo_period_nsec=[EMCMOT]SERVO_PERIOD num_joints=[KINS]JOINTS
loadrt hal_parport cfg="0 out"
setp parport.0.reset-time 5000
loadrt stepgen step_type=0,0,0
loadrt pwmgen output_type=1

addf parport.0.read base-thread
addf stepgen.make-pulses base-thread
addf pwmgen.make-pulses base-thread
addf parport.0.write base-thread
addf parport.0.reset base-thread

addf stepgen.capture-position servo-thread
addf motion-command-handler servo-thread
addf motion-controller servo-thread
addf stepgen.update-freq servo-thread
addf pwmgen.update servo-thread

net spindle-cmd-rpm => pwmgen.0.value
net spindle-on <= spindle.0.on => pwmgen.0.enable
net spindle-pwm <= pwmgen.0.pwm
setp pwmgen.0.pwm-freq 100.0
setp pwmgen.0.scale 1166.6666666666665
setp pwmgen.0.offset 0.11428571428571428
setp pwmgen.0.dither-pwm true
net spindle-cmd-rpm <= spindle.0.speed-out
net spindle-cmd-rpm-abs <= spindle.0.speed-out-abs
net spindle-cmd-rps <= spindle.0.speed-out-rps
net spindle-cmd-rps-abs <= spindle.0.speed-out-rps-abs
net spindle-at-speed => spindle.0.at-speed
net spindle-cw <= spindle.0.forward

net estop-out => parport.0.pin-01-out
net xstep => parport.0.pin-02-out
setp parport.0.pin-02-out-reset 1
net xdir => parport.0.pin-03-out
net ystep => parport.0.pin-04-out
setp parport.0.pin-04-out-reset 1
net ydir => parport.0.pin-05-out
net zstep => parport.0.pin-06-out
setp parport.0.pin-06-out-reset 1
net zdir => parport.0.pin-07-out
net astep => parport.0.pin-08-out
setp parport.0.pin-08-out-reset 1
net adir => parport.0.pin-09-out
net spindle-cw => parport.0.pin-14-out
net spindle-pwm => parport.0.pin-16-out
net xenable => parport.0.pin-17-out

setp stepgen.0.position-scale [JOINT_0]SCALE
setp stepgen.0.steplen 1
setp stepgen.0.stepspace 0
setp stepgen.0.dirhold 37000
setp stepgen.0.dirsetup 37000
setp stepgen.0.maxaccel [JOINT_0]STEPGEN_MAXACCEL
net xpos-cmd joint.0.motor-pos-cmd => stepgen.0.position-cmd
net xpos-fb stepgen.0.position-fb => joint.0.motor-pos-fb
net xstep <= stepgen.0.step
net xdir <= stepgen.0.dir
net xenable joint.0.amp-enable-out => stepgen.0.enable

setp stepgen.1.position-scale [JOINT_1]SCALE
setp stepgen.1.steplen 1
setp stepgen.1.stepspace 0
setp stepgen.1.dirhold 37000
setp stepgen.1.dirsetup 37000
setp stepgen.1.maxaccel [JOINT_1]STEPGEN_MAXACCEL
net ypos-cmd joint.1.motor-pos-cmd => stepgen.1.position-cmd
net ypos-fb stepgen.1.position-fb => joint.1.motor-pos-fb
net ystep <= stepgen.1.step
net ydir <= stepgen.1.dir
net yenable joint.1.amp-enable-out => stepgen.1.enable

setp stepgen.2.position-scale [JOINT_2]SCALE
setp stepgen.2.steplen 1
setp stepgen.2.stepspace 0
setp stepgen.2.dirhold 37000
setp stepgen.2.dirsetup 37000
setp stepgen.2.maxaccel [JOINT_2]STEPGEN_MAXACCEL
net zpos-cmd joint.2.motor-pos-cmd => stepgen.2.position-cmd
net zpos-fb stepgen.2.position-fb => joint.2.motor-pos-fb
net zstep <= stepgen.2.step
net zdir <= stepgen.2.dir
net zenable joint.2.amp-enable-out => stepgen.2.enable

net estop-out <= iocontrol.0.user-enable-out
net estop-out => iocontrol.0.emc-enable-in

loadusr -W hal_manualtoolchange
net tool-change iocontrol.0.tool-change => hal_manualtoolchange.change
net tool-changed iocontrol.0.tool-changed <= hal_manualtoolchange.changed
net tool-number iocontrol.0.tool-prep-number => hal_manualtoolchange.number
net tool-prepare-loopback iocontrol.0.tool-prepare => iocontrol.0.tool-prepared

I've wired the A and B outputs to two drivers (so according to the breakout board I now have X,Y,A and . I've made an attempt to configure the ini and hal files - X and Y are working, but a U or V G1 does nothing

Managed to figure this out - I have independent X,Y,U and V working now. If anyone wants the config files, let me be more helpful than the forum was

You could make a 'filter' program to remove the U and V automatically before loading the program.
linuxcnc.org/docs/devel/html/gui/filter-programs.html

Using XY/UV is probably best if running LinuxCNC, then you can use the special "FOAM" mode supported by Axis (At least, other GUIs may also support this)

linuxcnc.org/docs/html/gui/axis.html#_us...in_foam_cutting_mode