ok it took me a little longer to get this up, but this is my current version of the initial automatic filament calibration script.
It will automatically calibrate the e-steps and the non linear extrusion.
It will only run in 3.5 and as a macro.
The copyright of the script is
Tim Schneider
Meltingplot GmbH
CC BY-SA
content of 0:/macros/meltingplot/filament-extrusion-calibration
if !exists(global.ignoreMFMevents)
global ignoreMFMevents = true
else
set global.ignoreMFMevents = true
var filamentMonitorPin = "e1stop"
var filamentMonitorCircumference = 25.3
var extrusionDistance = 20 ; distance for e-step calibration
; speeds in mm/s for NLE to test
var extrusionSpeeds = {0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0}
M107 ; fan off
T0 ; select tool 0
M98 P"0:/sys/meltingplot/home_if_necessary" ; check homing
G29 S1 ; load stored hight map
M83 ; use relative distances for extrusion
G90 ; use absolute coordinates
G21 ; set units to millimeters
var currentTool = state.currentTool
var currentHeater = tools[0].heaters[var.currentTool]
var currentTemp = heat.heaters[var.currentHeater].active
if var.currentTemp < 180 || var.currentTemp > 355
set var.currentTemp = 180
M291 P"Please set desired filament temperature" R"Filament Temp" S6 L180 H355 F{var.currentTemp}
set var.currentTemp = input
G10 P0 S{var.currentTemp}
M116 ; wait for all heaters
G11 ; unretract
G1 Z300 F3600 ; raise z=20mm
G53 G1 X50 Y50 F14400 ; move printhead to center
G92 E0 ; reset e-steps
M220 S100 ; Set speed factor override percentage
M221 S100 ; Set extrude factor override percentage
M572 D0 S0.0 ; disable pressure advance
M592 D0 A0.0 B0.0 ; disable non-linear-extrusion
M591 D0 P0
G4 S1
M591 D0 P3 C{var.filamentMonitorPin} S2 R98:102 E0.2 L{var.filamentMonitorCircumference} ; enable MFM on all moves
G4 S5 ; wait for restart of MFM
G91 ; relative moves
; 15mm
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
; the mfm should be calibrated now
if sensors.filamentMonitors[0].calibrated == null
echo "Cannot calibrate filament monitor within 15mm - error!"
set global.ignoreMFMevents = false
M99
G4 S1 ; wait for filament monitor send timeout
; start e-step calibration
var totalDistanceBase = (sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev * sensors.filamentMonitors[0].configured.mmPerRev)
G1 X{var.extrusionDistance} E{var.extrusionDistance} F30
G4 S1 ; wait for filament monitor send timeout
var currentMeasured = (sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev * sensors.filamentMonitors[0].configured.mmPerRev)
var newESteps = {floor(move.extruders[0].stepsPerMm / ((var.currentMeasured-var.totalDistanceBase)/var.extrusionDistance)*100)/100}
set var.totalDistanceBase = (sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev * sensors.filamentMonitors[0].configured.mmPerRev)
G1 X{var.extrusionDistance} E{var.extrusionDistance} F30
G4 S1 ; wait for filament monitor send timeout
set var.currentMeasured = (sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev * sensors.filamentMonitors[0].configured.mmPerRev)
set var.newESteps = var.newESteps + {floor(move.extruders[0].stepsPerMm / ((var.currentMeasured-var.totalDistanceBase)/var.extrusionDistance)*100)/100}
set var.totalDistanceBase = (sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev * sensors.filamentMonitors[0].configured.mmPerRev)
G1 X{var.extrusionDistance} E{var.extrusionDistance} F30
G4 S1 ; wait for filament monitor send timeout
set var.currentMeasured = (sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev * sensors.filamentMonitors[0].configured.mmPerRev)
echo "Current E-Steps: " ^ {move.extruders[0].stepsPerMm}
set var.newESteps = (var.newESteps + {floor(move.extruders[0].stepsPerMm / ((var.currentMeasured-var.totalDistanceBase)/var.extrusionDistance)*100)/100})
set var.newESteps = floor(var.newESteps / 3.0 * 100)/100
echo "New E-Steps: " ^ var.newESteps
echo >{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-esteps.g"} "; calibration temperature: " ^ var.currentTemp
echo >>{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-esteps.g"} "M92 E" ^ var.newESteps
M92 E{var.newESteps} ; activate new e-steps
; start non linear calibration
G92 E0 ; reset e-steps
; https://www.bragitoff.com/2018/06/polynomial-fitting-c-program/
; speed to test
var x = var.extrusionSpeeds
; number of data points
var N = #var.x
; degree of polynomial
var n = 2
; echo "x: " ^ var.x
; echo "N: " ^ var.N
; echo "n: " ^ var.n
; array to store the y-axis data points
var y = vector(var.N, 0.0)
; gather y data points
;set var.y = {0.0, 0.0, 0.0118, 0.0207, 0.0247, 0.0356, 0.0507, 0.0613, 0.0751, 0.0922, 0.1234, 0.1438}
M591 D0 P0
G4 S1
M591 D0 P3 C{var.filamentMonitorPin} S2 R98:102 E0.2 L{var.filamentMonitorCircumference} ; enable MFM on all moves
G4 S5 ; wait for restart of MFM
G91 ; relative moves
; 15mm
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
G1 X1 E1 F30
; the mfm should be calibrated now
if sensors.filamentMonitors[0].calibrated == null
echo "Cannot calibrate filament monitor within 15mm - error!"
set global.ignoreMFMevents = false
M99
G4 S1 ; wait for filament monitor send timeout
; sensors.filamentMonitors[0].calibrated.totalDistance is including extrusion correction like pressure advance, non linear extrusion and so on ...
; move.extruders[0].rawPosition is the extrusion without correction values
; sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev is the number of measured revolutions
var i = 0
var first = true
var check = false
var nle_a = 0
var nle_b = 0
var nn = var.n
var success = false
var mean_error = 0.0
var min_error = 100.0
var max_error = 0.0
var s = 0.0
while true
; gather y-values for the compensated x-values
set var.i = 0
set var.n = var.nn
set var.mean_error = 0.0
set var.min_error = 100.0
set var.max_error = 0.0
var errors = vector(var.N, 0.0)
while {var.i < var.N}
set var.totalDistanceBase = (sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev * sensors.filamentMonitors[0].configured.mmPerRev)
var comp_f = var.x[var.i] * 60
if var.check == false && var.first == false
set var.comp_f = var.comp_f * (1 + var.y[var.i])
var currentCommanded = 100
G1 X{mod(var.i,2)=0?100:-100} E{var.currentCommanded} F{var.comp_f}
G4 S1 ; wait for filament monitor send timeout
set var.currentMeasured = (sensors.filamentMonitors[0].calibrated.totalDistance / sensors.filamentMonitors[0].calibrated.mmPerRev * sensors.filamentMonitors[0].configured.mmPerRev)
var error = (1.0-((var.currentMeasured-var.totalDistanceBase)/var.currentCommanded))
set var.min_error = min(var.min_error, var.error)
set var.max_error = max(var.max_error, var.error)
set var.errors[var.i] = var.error
echo "F" ^ {var.comp_f} ^ ": " ^ {var.error*100.0} ^ "% error."
if var.comp_f < 60 && var.error >= 0.1
echo "The filament error exceeds the expected value at low speed. This may be due to grinding. Repeating!"
G1 E-10 F60 ; backoff some filament
G1 E15 F60 ; extrude some material to get pass the grinding
continue
if var.check == false
set var.y[var.i] = var.error
if var.y[var.i] < 0.01
if var.first == true && var.i < 1 && var.y[var.i] < -0.01
echo "Calibrate E-Steps first."
M99
set var.y[var.i] = 0.01
; if the error is larger than 10% or more than twice as the previous value - stop
if var.y[var.i] > 0.1 || ( var.i > 0 && var.y[var.i-1] > 0.025 && var.y[var.i] > (var.y[var.i-1] * 2))
if var.first == true && var.i < 1
echo "Calibrate E-Steps first."
M99
set var.N = var.i
echo "New N: " ^ var.N
break
set var.i = var.i + 1
set var.first = false
var k = 0
while {var.k < var.N}
set var.mean_error = var.mean_error + var.errors[var.k]
set var.k = var.k + 1
set var.mean_error = var.mean_error / var.N
echo "mean error:" ^ var.mean_error
set var.k = 0
set var.s = 0.0
while {var.k < var.N}
set var.s = pow(var.errors[var.k] - var.mean_error, 2.0)
set var.k = var.k + 1
set var.s = sqrt(var.s / var.N)
echo "standard deviation: " ^ var.s
if var.check
set var.check = false
if var.s <= 0.005
set var.success = true
break
elif var.s > 0.005 && var.s < 0.25
M592 D0 A0 B0
continue
else
set var.success = false
break
; echo "y: " ^ var.y
; an array of size 2*n+1 for storing N, Sig xi, Sig xi^2, ...
var X = vector(2*var.n+1, 0.0)
; echo "X: " ^ var.X
set var.i = 0
while {var.i <= (2*var.n)}
var j = 0
while {var.j < var.N}
set var.X[var.i] = var.X[var.i] + pow(var.x[var.j], var.i)
set var.j = var.j + 1
set var.i = var.i + 1
; echo "X: " ^ var.X
; the normal argumented matrix
var B = vector(var.n+1, vector(var.n+2, 0.0))
var Y = vector(var.n+1, 0.0)
; echo "B: " ^ var.B
; echo "Y: " ^ var.Y
set var.i = 0
while {var.i <= var.n}
var j = 0
while {var.j < var.N}
set var.Y[var.i] = var.Y[var.i] + pow(var.x[var.j], var.i) * var.y[var.j]
set var.j = var.j + 1
set var.i = var.i + 1
; echo "Y: " ^ var.Y
set var.i = 0
while {var.i <= var.n}
var j = 0
while {var.j <= var.n}
set var.B[var.i][var.j] = var.X[var.i+var.j]
set var.j = var.j + 1
set var.i = var.i + 1
; echo "B: " ^ var.B
set var.i = 0
while {var.i <= var.n}
set var.B[var.i][var.n+1] = var.Y[var.i]
set var.i = var.i + 1
; echo "B: " ^ var.B
var A = vector(var.n+1, 0.0)
; echo "A: " ^ var.A
; gaussEliminationLS
var m = var.n + 1
set var.n = var.n + 2
set var.i = 0
while {var.i < (var.m-1)}
;Partial Pivoting
set var.k = var.i + 1
while {var.k < var.m}
;If diagonal element(absolute vallue) is smaller than any of the terms below it
if abs(var.B[var.i][var.i]) < abs(var.B[var.k][var.i])
;Swap the rows
var j = 0
while {var.j < var.n}
var temp = var.B[var.i][var.j]
set var.B[var.i][var.j] = var.B[var.k][var.j]
set var.B[var.k][var.j] = var.temp
set var.j = var.j + 1
set var.k = var.k + 1
;Begin Gauss Elimination
set var.k = var.i + 1
while {var.k < var.m}
var term = var.B[var.k][var.i] / var.B[var.i][var.i]
var j = 0
while {var.j < var.n}
set var.B[var.k][var.j] = var.B[var.k][var.j] - var.term * var.B[var.i][var.j]
set var.j = var.j + 1
set var.k = var.k + 1
set var.i = var.i + 1
;Begin Back-substitution
set var.i = var.m - 1
while {var.i >= 0}
set var.A[var.i] = var.B[var.i][var.n-1]
var j = var.i + 1
while {var.j < (var.n - 1)}
set var.A[var.i] = var.A[var.i] - var.B[var.i][var.j] * var.A[var.j]
set var.j = var.j + 1
set var.A[var.i] = var.A[var.i] / var.B[var.i][var.i]
set var.i = var.i - 1
set var.nle_a = var.A[1]
set var.nle_b = var.A[2]
M592 D0 A{var.A[1]} B{var.A[2]} L0.2
echo "Test: M592 D0 A" ^ var.nle_a ^ " B" ^ var.nle_b ^ " L0.2"
set var.check = true
if var.success
echo "NLE calibration finished!"
echo "M592 D0 A" ^ var.nle_a ^ " B" ^ var.nle_b ^ " L0.2"
echo >{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"} "; max F" ^ var.x[var.N-1] * 60 ^ " mm/min or " ^ var.x[var.N-1] * 6.38 ^ "mm³/s"
echo >>{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"} "; temp: " ^ var.currentTemp ^ " °C"
echo >>{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"} "; mean error: " ^ var.mean_error
echo >>{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"} "; min error: " ^ var.min_error
echo >>{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"} "; max error: " ^ var.max_error
echo >>{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"} "; standard deviation: " ^ var.s
echo >>{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"} "M592 D0 A" ^ var.nle_a ^ " B" ^ var.nle_b ^ " L0.2"
else
echo "NLE calibration falied!"
; end calibration
G10 ; retract
G10 P0 R0 S0 ; disable hotend
M140 S0 R0 ; set bed heater to 0°
M144 P0 ; disable bed heater
T-1 ; unselect tool
M591 D0 P0 ; reset filament sensor
M98 P"0:/sys/meltingplot/machine-override" ; Load Machine specific overrides
set global.ignoreMFMevents = false
add the following lines to your 0:/sys/filament-error.g
if exists(global.ignoreMFMevents) && global.ignoreMFMevents == true
M99
and the following to your filament config
if fileexists({"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-esteps.g"})
M98 P{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-esteps.g"}
if fileexists({"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"})
M98 P{"0:/filaments/" ^ {move.extruders[0].filament} ^ "/config-auto-nle.g"}
the macro M98 P"0:/sys/meltingplot/machine-override" will reset the filament monitor to its default, so you need to adapt this.
sample output
Another thing I would like to add is pressure advance calibration, as I think, it should be possible to determine the stiffness of the filament with the filament monitor and predict the pressure advance value. Maybe somesome can help here?
Btw. this script helped me to write a simple adaptive temp control in correlation to the extrusion speed, which will crank up the extrusion flow rate upto 30% and make the NLE look linear. Maybe something for the firmware @dc42
content of daemon.g
while true
if exists(global.initial_temp) == false
global initial_temp = 0
if !exists(global.compensated_temp)
global compensated_temp = 0
if !exists(global.is_compensated)
global is_compensated = false
if !exists(global.filament_extrusion_temp_compensation_factor)
global filament_extrusion_temp_compensation_factor = 1
if exists(global.filament_extrusion_temp_compensation) && global.filament_extrusion_temp_compensation
if ( {move.currentMove.extrusionRate} > 0 )
if global.initial_temp == 0 || global.compensated_temp != {heat.heaters[1].active}
set global.initial_temp = {heat.heaters[1].active}
set global.compensated_temp = global.initial_temp + min({move.currentMove.extrusionRate} * global.filament_extrusion_temp_compensation_factor, 100)
G10 P0 S{global.compensated_temp} R{global.initial_temp-50}
set global.is_compensated = true
elif (global.initial_temp != 0 && {heat.heaters[1].active} != 0 && global.is_compensated)
G10 P0 S{global.initial_temp} R{global.initial_temp-50}
set global.is_compensated = false
if you want to use the temp compensation add the following to your filament config and rerun the auto filament calibration
set global.filament_extrusion_temp_compensation_factor = 8
if !exists(global.filament_extrusion_temp_compensation)
global filament_extrusion_temp_compensation = true
not rock solid, as I can still crash it - but mostly solid 
