Homemade, cheap, plasma CNC

Thanks Tommy, I’ll try that tonight when I get down to the shed. 

Still not working,

linux configuration safe height 20 (as per tommy suggestion), Sheet cam rapid clearance 30mm.

Z axis drives down, slows to probe, probes and cuts, goes up 8.4mm ( no idea why it only goes this high) travels to next cut, goes up, begins probe.

 

Post screenshots of "run" and "config" tabs please.
Jog the torch down to just under where the slats start (no material on table) then click on the "touch off" button, make sure Z axis is selected.
Also the Z axis and joint section of the ini file would help.

RNJFAB wrote:

Still not working,

linux configuration safe height 20 (as per tommy suggestion), Sheet cam rapid clearance 30mm.

This SheetCam setting is not used, all Z settings are internal and set from the parameters tab.

Z axis drives down, slows to probe, probes and cuts, goes up 8.4mm ( no idea why it only goes this high) travels to next cut, goes up, begins probe.

It goes up because your Probe Height may be higher than your Safe Height.

Are you still getting the Safe Height warning? If you do when exactly are you getting it?

Can you post a backup of your config.

Hope this is everything. About to run back to the house, just had a storm start here. We have just spent the last week in flood. aaahhhhhhhhhh



z axis from .ini.

#******************************************
[AXIS_Z]
# MAX_VEL & MAX_ACC need to be twice the corresponding joint value
MAX_VELOCITY = 80
MAX_ACCELERATION = 1000.0
OFFSET_AV_RATIO = 0.5
MIN_LIMIT = -150
MAX_LIMIT = 15


[JOINT_3]
TYPE = LINEAR
HOME = 0.0
FERROR = 10.0
MIN_FERROR = 1.0
MAX_VELOCITY = 40.0
MAX_ACCELERATION = 500.0
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 50
STEPGEN_MAXACCEL = 600
P = 1000.0
I = 0.0
D = 0.0
FF0 = 0.0
FF1 = 1.0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 0.0
# these are in nanoseconds
DIRSETUP   = 10000
DIRHOLD    = 10000
STEPLEN    = 10000
STEPSPACE  = 10000
STEP_SCALE = -160.0
MIN_LIMIT = -150
MAX_LIMIT = 15
HOME_OFFSET = 0
HOME_SEARCH_VEL = 25
HOME_LATCH_VEL = -5
HOME_FINAL_VEL = 20
HOME_IGNOR_LIMITS = YES
HOME_SEQUENCE = 1

Yeah safe height is lower than probe height, it must be higher.
Safe height is where the torch is retracted to before G0 or before it moves from cut to cut.
I have it at 120 as my travel is 180 in total after homing, so i have space to spare.

A helpful visual of the different heights:   linuxcnc.org/docs/devel/html/plasma/qtpl...tml#qt_initial-setup

Thanks guys,

I have changed the safe height to 100 and still get the same error. 

The z axis only goes up to 8.4mm before travel. And gives the warning after the first cut of a job. 

No doubt I have set something, somewhere and now I can’t find it to fix it. 

I set up a sim with the same parameters for the Z axis that you posted and it works fine with the plasmac example files.
Can you post the backup of your config.
Can you post a Gcode file it errors with.
Can you pinpoint exactly on the Gcode file where it errors.

Thanks Phil,

config
 

G code. error happens at line 17. once touchoff has been completed.