i need help switching my setting to mm

My machine is set in inches, this is the only way i could make it work. anyway i tried converting all the setting to mm and the machine wont move and i am not sure why?


the reason why i want to set my machine to mm is that i use a program for cutting surfboard, boardcad and it generate all the gcode in mm.

is someone could help me?

or maybe there is a way to switch to mm on the fly?

i tried attaching my ini file but wont let me attach it.


here it is:

Generated by stepconf at Mon Feb 11 18:12:54 2013
# If you make changes to this file, they will be
# overwritten when you run stepconf again

[EMC]
MACHINE = PMDX-126_2012-08-03
DEBUG = 0

[DISPLAY]
DISPLAY = axis
EDITOR = gedit
POSITION_OFFSET = RELATIVE
POSITION_FEEDBACK = ACTUAL
MAX_FEED_OVERRIDE = 1.2
INTRO_GRAPHIC = linuxcnc.gif
INTRO_TIME = 5
PROGRAM_PREFIX = /home/louis/linuxcnc/nc_files
INCREMENTS = .1in .05in .01in .005in .001in .0005in .0001in

[FILTER]
PROGRAM_EXTENSION = .png,.gif,.jpg Greyscale Depth Image
PROGRAM_EXTENSION = .py Python Script
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
COMM_WAIT = 0.010
BASE_PERIOD = 30682
SERVO_PERIOD = 1000000

[HAL]
HALFILE = PMDX-126_2012-08-03.hal
HALFILE = custom.hal
POSTGUI_HALFILE = custom_postgui.hal

[TRAJ]
AXES = 4
COORDINATES = X Y Z A
MAX_ANGULAR_VELOCITY = 16.00
DEFAULT_ANGULAR_VELOCITY = 1.60
LINEAR_UNITS = inch
ANGULAR_UNITS = degree
CYCLE_TIME = 0.010
DEFAULT_VELOCITY = 1.60
MAX_LINEAR_VELOCITY = 16.00

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

[AXIS_0]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 15.2001862935
MAX_ACCELERATION = 17.0
STEPGEN_MAXACCEL = 21.25
SCALE = 2037.0
FERROR = 0.05
MIN_FERROR = 0.01
MIN_LIMIT = -142.0
MAX_LIMIT = 0.01
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = 0.8
HOME_LATCH_VEL = -0.050000
HOME_IGNORE_LIMITS = YES
HOME_SEQUENCE = 1

[AXIS_1]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 15.2001862935
MAX_ACCELERATION = 17.0
STEPGEN_MAXACCEL = 21.25
SCALE = 2037.0
FERROR = 0.05
MIN_FERROR = 0.01
MIN_LIMIT = -37.0
MAX_LIMIT = 0.01
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = 0.8
HOME_LATCH_VEL = -0.050000
HOME_IGNORE_LIMITS = YES
HOME_SEQUENCE = 2

[AXIS_2]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 3.7
MAX_ACCELERATION = 20.0
STEPGEN_MAXACCEL = 25.0
SCALE = 4000.0
FERROR = 0.05
MIN_FERROR = 0.01
MIN_LIMIT = -15.0
MAX_LIMIT = 0.01
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = 0.8
HOME_LATCH_VEL = -0.050000
HOME_IGNORE_LIMITS = YES
HOME_SEQUENCE = 0

[AXIS_3]
TYPE = ANGULAR
HOME = 0.0
MAX_VELOCITY = 16.0
MAX_ACCELERATION = 17.0
STEPGEN_MAXACCEL = 21.25
SCALE = 19.6367206676
FERROR = 1
MIN_FERROR = .25
MIN_LIMIT = -37.0
MAX_LIMIT = 0.01
HOME_OFFSET = 0.0

i was able to make the mm work but my problem is the machine move in wrong distance.
i dont undertsand how to set my pitch.
the acme screw has 11 thread per inch but i want my machine in mm so 0.44 thread per mm.

also for X and Y i have a pulley,
the setup is made by cnc router parts, its called the nema 34 pro. it has 64 teeth and the ratio is 3:2:1
the gear rack has 20 pitch (rack and pinion setup)

now is someone can help figure out my stepconf and where to put this info.

i am getting very close, everthying is moving, linuxcnc is super smoot, i just have trouble with the right distance.


thanks for your input, its been countless hours in trying to make this work, i have a xml file for mach giving by the supplier. thanks JohnT to convert it but didnt work so i am trying to setup from scratch.

cheers!

metric is 25.4mm per inch

10 TPI is the same as 2.54mm pitch.
So the movement will be 2.54mm for each turn

in your case 20 tpi = 5.08 mm ( 2x 2.54mm )

if you use stepconf in metric mode and use 5.08 as the leadscrew pitch should help

what did not work with the mach converson ?
why do you wish to switch a Imperial machine to metric ?

you could end up with errors due to the maths in rounding etc ...

if you just wish to switch to metric mode in your code use G20 - G21

Hello,

I do not see what the micro stepping is set at which will also effect your pitch.

SCALE is the item you want to edit in your config file.
I often find it faster to have the machine make a move of a know distance and then measure the actual movement.
Then look at your SCALE for that axis adjust it by hand by editing the config file to get it right.
For example where your SCALE is 4000 and the machine moves twice as far as expected change the SCALE to 2000 and test (4000 / 2 = 2000).

Rick G

how the cncrp rack drives work
the pinion has a 1" pitch circle, so each rev of the pinion is 3.14159"
with a 3.2:1 belt ratio: 3.14159" / 3.2 = 0.98174" per motor revolution
200 steps per rev / 0.98174inches per rev = 203.718 steps per inch
with 10x microstepping thats 2037.18 steps per inch.

Leave your settings at that scale,
If you want to move the machine in metric then use G21

set your machine up using Imperial , then use G21 in your gcode , will do the conversion automaticly

i see your other post regarding your script for probing , this script could easily be changed to use Imperial Inch
so you could have the option of both , also i would suggest looking at your board maker program it should have an option to also produce Inch output i would have thought ,

i'm away today , but i could have a look on my return

the gcode tutorials would be a good start , programs only tell you half the story , you need to be able to modify afterwards .