Only probe where the part will be printed

RatRig0331

I know this was brought up a few times and I’m finding it hard to follow the timeline from 2020 for mesh probing only where the part will be printed I’m using a rat rig v-500 with prusa slicer. I read it can be done and I’ve tryed following the chat instructions but have had no luck and was hoping someone would be willing to hold my hand on this one to get the bed mesh only probing where the part will be printing.

OwenD

Here's how I do it.
I'm sure there's may other ways.
EDIT: I added my heating calls in superslicer because I realised I turn the heaters off in the probing, so you must heat after.

In config.g I call this macro to set my initial probe points
I also do this any other time I want to reset them to the full bed size.
M98 P"0:/sys/setDefaultProbePoints.g" ; define default mesh grid

;0:/sys/setDefaultProbePoints.g
var SafeZone = 10
var MinReachableX = (sensors.probes[0].offsets[0] + var.SafeZone)
var MaxReachabeX = (move.axes[0].max - sensors.probes[0].offsets[0] - var.SafeZone)
var MinReachableY =  (sensors.probes[0].offsets[1] + var.SafeZone)
var MaxReachabeY = (move.axes[1].max - sensors.probes[0].offsets[1] - var.SafeZone)

M557 X{var.MinReachableX,var.MaxReachabeX} Y{var.MinReachableY,var.MaxReachabeY} S30; define mesh grid

if !exists(global.minProbeX)
	global minProbeX = move.compensation.probeGrid.mins[0]
else
	set global.minProbeX = move.compensation.probeGrid.mins[0]

if !exists(global.minProbeY)
	global minProbeY = move.compensation.probeGrid.mins[1]
else
	set global.minProbeY = move.compensation.probeGrid.mins[1]

if !exists(global.maxProbeX)
	global maxProbeX = move.compensation.probeGrid.maxs[0]
else
	set global.maxProbeX = move.compensation.probeGrid.maxs[0]

if !exists(global.maxProbeY)
	global maxProbeY = move.compensation.probeGrid.maxs[1]
else
	set global.maxProbeX = move.compensation.probeGrid.maxs[1]

In Prusa/Superslicer I have

set global.minProbeX = {first_layer_print_min[0]}
set global.maxProbeX = {first_layer_print_max[0]}
set global.minProbeY = {first_layer_print_min[1]}
set global.maxProbeY = {first_layer_print_max[1]}
T[current_extruder] ; select tool 
M568 P[current_extruder] R{"{heat.coldExtrudeTemperature+5}"} S[first_layer_temperature_0] A1 ; (set extruder to stanby to soften any protruding filament before probing )
M106 P[current_extruder] S0 ;Start with fan off
M118 S"Heating Bed"
G4 S1
M140 S[first_layer_bed_temperature_0]  R{bed_temperature[0]-20}; Set fast bed temp & standby - Standby is 20 degrees less than normal.
M116 ; Wait for bed before doing mesh probe.
G29 ; do mesh for printed area
G29 S1  ; load small mesh
M568 P[current_extruder] R{"{heat.coldExtrudeTemperature+5}"} S[first_layer_temperature_0] A2 ; (set standby and active temperatures for active tool.  Standby is 5 degrees above cold extrude temp )
M116 ; wait for temps

In mesh.g I have

;0:/sys/mesh.g
; run when G29 with no paramters is called.
; if this file not found G29 S0 will run
var m557MinX = 40;  ; put your default here
var m557MaxX = 180;  ; put your default here
var m557MinY = 20;  ; put your default here
var m557MaxY = 180;  ; put your default here
var MinSpace = 10 ; put default minimum spacing
var MaxSpace = 30 ; put default maximum spacing
var ProbeNumX = 8 ; put default probe points
var ProbeNumY = 8 ; put default probe points.
var ProbeCenterX = 90 ; will be updated to probe centre of print
var ProbeCenterY = 90 ; will be updated to probe centre of print

var MaxProbePoints = max(floor(move.axes[0].max / var.MaxSpace),floor(move.axes[1].max / var.MaxSpace)) ; maximum points in either axis

echo "Maximum allowed probe points is " ^ var.MaxProbePoints ^ " using max space of " ^ var.MaxSpace
var SafeZone = 3 ; safety margin for probing near edge.

if exists(global.minProbeX)
	if global.minProbeX < (sensors.probes[0].offsets[0] + var.SafeZone)
		echo "minProbeX (" ^ global.minProbeX ^ ") unreachable - reset to " ^ (sensors.probes[0].offsets[0] + var.SafeZone)
		set global.minProbeX = (sensors.probes[0].offsets[0] + var.SafeZone)
	set var.m557MinX = global.minProbeX

if exists(global.maxProbeX)
	if global.maxProbeX < (global.minProbeX + (var.MinSpace*2))
		set global.maxProbeX = (global.minProbeX + (var.MinSpace*2))
	if global.maxProbeX > (move.axes[0].max - sensors.probes[0].offsets[0] - var.SafeZone)
		echo "maxProbeX (" ^ global.maxProbeX ^ ") unreachable - reset to " ^ (move.axes[0].max - sensors.probes[0].offsets[0] - var.SafeZone)
		set global.maxProbeX = (move.axes[0].max - sensors.probes[0].offsets[0] - var.SafeZone)
	set var.m557MaxX = global.maxProbeX

if exists(global.minProbeY)
	if global.minProbeY < (sensors.probes[0].offsets[1] + var.SafeZone)
		echo "minProbeY (" ^ global.minProbeY ^ ") unreachable - reset to " ^ (sensors.probes[0].offsets[1] + var.SafeZone)
		set global.minProbeY = (sensors.probes[0].offsets[1] + var.SafeZone)
	set var.m557MinY = global.minProbeY


if exists(global.maxProbeY)
	if global.maxProbeY < (global.minProbeY + (var.MinSpace*2))
		set global.maxProbeY = (global.minProbeY + (var.MinSpace*2))
	if global.maxProbeY > (move.axes[1].max - sensors.probes[0].offsets[1] - var.SafeZone)
		echo "maxProbeY (" ^ global.maxProbeY ^ ") unreachable - reset to " ^ (move.axes[1].max - sensors.probes[0].offsets[1] - var.SafeZone)
		set global.maxProbeY = (move.axes[1].max - sensors.probes[0].offsets[1] - var.SafeZone)
	set var.m557MaxY = global.maxProbeY

echo "Probing grid - X" ^ var.m557MinX ^ ":" ^ var.m557MaxX ^ " Y" ^ var.m557MinY ^ ":" ^ var.m557MaxY

var MinProbesX = floor((var.m557MaxX - var.m557MinX) / var.MaxSpace)
;echo "Min Probes X is " ^ var.MinProbesX

var MaxProbesX = floor((var.m557MaxX - var.m557MinX) / var.MinSpace)
;echo "Max Probes X is " ^ var.MaxProbesX

set var.ProbeNumX = min(var.MaxProbePoints,var.MaxProbesX)

var MinProbesY = floor((var.m557MaxY - var.m557MinY) / var.MaxSpace)
;echo "Min Probes Y is " ^ var.MinProbesY

var MaxProbesY = floor((var.m557MaxY - var.m557MinY) / var.MinSpace)
;echo "Max Probes Y is " ^ var.MaxProbesY

set var.ProbeNumY = min(var.MaxProbePoints,var.MaxProbesY)

; sanity check probe points
if var.ProbeNumX<2
	set var.ProbeNumX=2
if var.ProbeNumY<2
	set var.ProbeNumY=2

if var.ProbeNumX > var.MaxProbePoints
	set var.ProbeNumX = var.MaxProbePoints

if var.ProbeNumY > var.MaxProbePoints
	set var.ProbeNumY = var.MaxProbePoints

if (var.ProbeNumX * var.ProbeNumY) > 441
	if var.ProbeNumX > 21
		set var.ProbeNumX = 21
		echo "Too many X points - reduced to 21"
	if var.ProbeNumY > 21
		set var.ProbeNumY = 21
		echo "Too many Y points - reduced to 21"
	
echo "Probing " ^ var.ProbeNumX ^ " points in X direction & " ^ var.ProbeNumY ^ " points in Y direction"

;check state of heaters
var bedState = heat.heaters[0].state
var bedActiveTemp = heat.heaters[0].active
var bedStandbyTemp = heat.heaters[0].standby
var nozzleState = heat.heaters[1].state
M140 P0 S-276 ; turn off bed heater
M568 P0 A0 ; turn off nozzle heater

; do probing
set var.ProbeCenterX = (global.maxProbeX - ((global.maxProbeX - global.minProbeX)/2)) ; calculate centre point of probe area
set var.ProbeCenterY = (global.maxProbeY - ((global.maxProbeY - global.minProbeY)/2)) ; calculate centre point of probe area
echo "Setting Z datum point at X" ^ var.ProbeCenterX ^ " Y" ^ var.ProbeCenterY
; set Z = 0 to centre of probe area
G1 X{var.ProbeCenterX- sensors.probes[0].offsets[0]} Y{var.ProbeCenterY- sensors.probes[0].offsets[1]} Z{sensors.probes[0].diveHeight+2} F3600
G30
echo "Mesh probing"
M557 X{var.m557MinX,var.m557MaxX} Y{var.m557MinY,var.m557MaxY} P{var.ProbeNumX,var.ProbeNumY}
if result != 0
	abort "ERROR: could not create mesh" 
else
	G29 S0
	if result != 0
		abort "ERROR: Mesh probing failed"
	else
		echo "Mesh probing successful.   Loading mesh.."

; set Z = 0 to centre of probe area
echo "Reset Z datum in mesh centre"
G1 X{var.ProbeCenterX- sensors.probes[0].offsets[0]} Y{var.ProbeCenterY- sensors.probes[0].offsets[1]} Z{sensors.probes[0].diveHeight+2} F3600
G30

; turn the heaters back on if needed
if var.bedState != "off"
	M140 S{var.bedActiveTemp} R{var.bedStandbyTemp}
	if var.bedState="active"
		M144 P0 S1 ; put bed on active temp
	else
		M144 P0 S0 ; put bed on standby temp
if var.nozzleState	!= "off"
	if var.nozzleState = "active"
		M568 P0 A2 ; set nozzle to active
	else
		M568 P0 A1 ; set nozzle to standby

RatRig0331

@owend how do you call that macro in your main config.g, and where in prusa slicer do you add the other macro?

RatRig0331

@owend I think I figured it out but I’m getting a error massage: unknown variable ‘global.minprobex’

OwenD

@ratrig0331
You need to put this line in config.g in place of your normal M557

M98 P"0:/sys/setDefaultProbePoints.g"

Then set all your default probe settings in the areas at the start of the macro.

In superslicer put all the code provided in your start gcode

dc42

@owend said in Only probe where the part will be printed:

set global.minProbeX = {first_layer_print_min[0]} 
set global.maxProbeX = {first_layer_print_max[0]} 
set global.minProbeY = {first_layer_print_min[1]} 
set global.maxProbeY = {first_layer_print_max[1]}
T[current_extruder] ; select tool
M568 P[current_extruder] R{"{heat.coldExtrudeTemperature+5}"} S[first_layer_temperature_0] A1 ; (set extruder to stanby to soften any protruding filament before probing )
M106 P[current_extruder] S0 ;Start with fan off

You appear to be using a mixture of { } and [ ] to surround named values that you want PrusaSlicer to substitute for. Which is correct?

OwenD

@dc42
The square brackets are legacy place holders, so should probably be replaced by curly brackets.
I just tried changing them all to curly brackets.
However in Superslicer at least, [first_layer_temperature_0] only seems to work with a square bracket.

EDIT
It seems things like [first_layer_temperature_0] have been replaced by {first_layer_temperature[0]}

I've revised the start Gcode related to probing to this (there are of course other commands need in the start code)

set global.minProbeX = {first_layer_print_min[0]}
set global.maxProbeX = {first_layer_print_max[0]}
set global.minProbeY = {first_layer_print_min[1]}
set global.maxProbeY = {first_layer_print_max[1]}
T{current_extruder} ; select tool 1
M568 P{current_extruder} R{"{heat.coldExtrudeTemperature+5}"} S{first_layer_temperature[current_extruder]} A1 ; (set extruder to stanby to soften any protruding filament before probing )
M106 P{current_extruder} S0 ;Start with fan off
M140 S{first_layer_bed_temperature[current_extruder]}  R{bed_temperature[0]-20}; Set fast bed temp & standby - Standby is 20 degrees less than normal.
M116 ; Wait for bed before doing mesh probe.
M561 ; clear any bed transform
G29 ; do mesh for printed area
G29 S1  ; load small mesh
G01 X0 Y{"{move.axes{1}.max}"} Z0.6  F1500 ; Move to back corner while heating
M568 P{current_extruder} R{"{heat.coldExtrudeTemperature+5}"} S{first_layer_temperature[current_extruder]} A2 ; (set standby and active temperatures for active tool.  Standby is 5 degrees above cold extrude temp )
M116 ; Wait for all temps to stabilise

RatRig0331

@owend when I restart I get this

Error: (sensors.probes[0].offsets[0] + var.SafeZone)array index out of bounds of setDefaultProbePoints.g

And if I try to start a print I get this

Error: unknown variable 'global.minProbeX'

dc42

@ratrig0331 have you opened the GCode file in a text editor, to see what the slicer has actually generated?

RatRig0331

@dc42 not yet I’ll take a look

RatRig0331

@dc42 it looks like its all there in the gcode

; external perimeters extrusion width = 0.40mm
; perimeters extrusion width = 0.40mm
; infill extrusion width = 0.40mm
; solid infill extrusion width = 0.40mm
; top infill extrusion width = 0.40mm
; first layer extrusion width = 0.45mm

M73 P0 R8
M107
M104 S205 ; set temperature
;TYPE:Custom
set global.minProbeX = 183.982
set global.maxProbeX = 316.018
set global.minProbeY = 188.982
set global.maxProbeY = 311.018
T0 ; select tool 1
M568 P0 R{heat.coldExtrudeTemperature+5} S205 A1 ; (set extruder to stanby to soften any protruding filament before probing )
M106 P0 S0 ;Start with fan off
M140 S68 R45; Set fast bed temp & standby - Standby is 20 degrees less than normal.
M116 ; Wait for bed before doing mesh probe.
M561 ; clear any bed transform
G29 ; do mesh for printed area
G29 S1 ; load small mesh
G01 X0 Y{move.axes{1}.max} Z0.6 F1500 ; Move to back corner while heating
M568 P0 R{heat.coldExtrudeTemperature+5} S205 A2 ; (set standby and active temperatures for active tool. Standby is 5 degrees above cold extrude temp )
M116 ; Wait for all temps to stabilise
M109 S205 ; set temperature and wait for it to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M83 ; use relative distances for extrusion
; Filament gcode
SET_GCODE_OFFSET Z=0
SET_PRESSURE_ADVANCE ADVANCE=0.05
M107
;LAYER_CHANGE
;Z:0.2
;HEIGHT:0.2
;BEFORE_LAYER_CHANGE
;0.2
G92 E0
;

this is what i changed in the mesh.g for my 500x500mm xycore

;0:/sys/mesh.g
; run when G29 with no paramters is called.
; if this file not found G29 S0 will run
var m557MinX = 25; ; put your default here
var m557MaxX = 450; ; put your default here
var m557MinY = 25; ; put your default here
var m557MaxY = 450; ; put your default here
var MinSpace = 10 ; put default minimum spacing
var MaxSpace = 30 ; put default maximum spacing
var ProbeNumX = 8 ; put default probe points
var ProbeNumY = 8 ; put default probe points.
var ProbeCenterX = 285 ; will be updated to probe centre of print
var ProbeCenterY = 270 ; will be updated to probe centre of print

var MaxProbePoints = max(floor(move.axes[0].max / var.MaxSpace),floor(move.axes[1].max / var.MaxSpace)) ; maximum points in either axis

echo "Maximum allowed probe points is " ^ var.MaxProbePoints ^ " using max space of " ^ var.MaxSpace
var SafeZone = 3 ; safety margin for probing near edge.

OwenD

@ratrig0331
Sounds like it's not finding a sensors.probe[0] when you run the initial setup from config.g
As that line is at the start of the macro, it never gets to the lines that set the global variables up.
Make sure your probe is configured before calling the macro.
Maybe post you config.g so we can see how your probe(s) are configured

RatRig0331

@owend

;;; BLTouch ;;;
M950 S0 C"io2.out" ; Create a servo pin on io2
M558 P9 C"io2.in" H5 F240 T10800 A5 ; set Z probe type to unmodulated and the dive height + speeds
G31 P25 X-29.00 Y-2.00 Z2.471

RatRig0331

@owend

;;; Endstops ;;;
M574 X1 S1 P"io1.in" ; configure active high endstops
M574 Y2 S1 P"io0.in" ; configure active high endstops
M574 Z1 S2

OwenD

@ratrig0331
Make sure
M98 P"0:/sys/setDefaultProbePoints.g"
Comes after your G31 in your BlTouch section

RatRig0331

@owend ok I’ll move it and give it a shot

RatRig0331

@owend that did the trick but now i need to turn down the amount of probe points
var MinSpace = 10 ; put default minimum spacing
var MaxSpace = 30 ; put default maximum spacing
var ProbeNumX = 8 ; put default probe points
var ProbeNumY = 8 ; put default probe points.
var ProbeCenterX = 285 ; will be updated to probe centre of print
var ProbeCenterY = 270 ; will be updated to probe centre of print

with my 100x100mm print its trying to do a 13x13 grid what do i tweak to lower that?

RatRig0331

@owend ok after letting it 100% there were more errors

8/14/2022, 10:15:03 PM Error: M557: bad grid definition: Spacing too small
8/14/2022, 10:14:19 PM Error: in GCode file line 773: G1: expected '}'

line 773 is your
G01 X0 Y{move.axes{1}.max} Z0.6 F1500 ; Move to back corner while heating

OwenD

@ratrig0331
Change your minSpace and maxSpace in the macro to reduce number of probe points
Try 50 & 100

The G1 is my bad
I did a search and replace when I was changing the braces, but changed one that should remain a square bracket

Change this line in superslicer
G01 X0 Y{"{move.axes{1}.max}"} Z0.6 F1500 ; Move to back corner while heating
To
G01 X0 Y{"{move.axes[1].max}"} Z0.6 F1500 ; Move to back corner while heating

Or delete the line if you don't want to move there while heating

RatRig0331

@owend

One down one to go I’m still getting the m557 error with the 50/100 spacing will this be normal a normal error from down sizing the bed mesh or is there a fix

Error: M557: bad grid definition: Spacing too small

——-Error: in GCode file line 773: G1: expected '}'———- is now fixed