Here is the modified script:
#!/usr/local/bin/python
# extrusion parameters (mm)
extrusion_width = 0.48 # typical: nozzleDiameter * 1.2 (f.e. a 0.4mm nozzle should be set to 0.48mm extrusion width in slicers)
layer_height = 0.2 # max: 50% of your extrusion_width
filament_diameter = 1.75 # manufacturers typically sell 1.73-1.74mm filament diameter (always lower than 1.75 to prevent cloggs) tested with many brands
# print speeds (mm/s)
travel_speed = 300
first_layer_speed = 10
speed = 60
cooling_fan_speed = 128 # from 0 to 255
# calibration object dimensions (mm)
layers = 80
object_width = 100
# pressure advance gradient (s)
layer_multiple = 3
pressure_advance_step = 0.01
# center of print bed (mm)
# needed to position this print in the middle of your print bed
# If you are not sure about this: Take a look into your slicer. Normally you will see the origin (center) visualized as xyz-axis
# f.e. I have a 285x220mm bed, my printers origin is at X0, Y0 (front left corner), so the offset value you would need for X are 285/2.0 = 142.5
offset_x = 100
offset_y = 100
layer0_z = layer_height
# put your typical start.gcode here, if you use a custom start gcode via your slicing software
# Python tipp: to type in a continuous command over multiple lines you can use a backslash '\'
# general tipp: to output a 'new line' after your gcode command use '\n' which is the representation of the new line byte sequence
# in short: use '\n\' after each line of your regular start.gcode command
try:
print('; START.gcode\n\
G90\n\
M82\n\
M106 S0\n\
M140 S60\n\
M190 S60\n\
M104 S240 T0\n\
M109 S240 T0\n\
G28 ; home all axes\n\
T0 ; set active extruder to 0\n\
M913 Y50 ; lower Y stepper torque to 50% ;if stall detection fails for protection of mechanics\n\
G1 X300 Y5 F1600;\n\
M913 Y100 ; raise Y stepper torque back to 100%\n\
G1 Z0.15 F400;\n\
G91 ; relative\n\
; wipe nozzle on beds edge \n\
G1 X-20 E10 F800;\n\
G1 X-15 Y10 E13 F1600;\n\
G1 X-35 E15;\n\
G92 E0; zero extruded length\n\
G90 ; absolute\n\
; process _R_Multimaterial-1\n\
; layer 1, Z = 0.220\n\
T0\n\
G92 E0.0000 ; reset extruded length \n\
')
except:
print(' !!! your start.gcode is faulty, check correct format')
exit()
print('\nM83 ; relative extrusion for this python script\n')
from math import sqrt
curr_x = offset_x
curr_y = offset_y
curr_z = layer0_z
def extrusion_volume_to_length(volume):
return volume / (filament_diameter * filament_diameter * 3.14159 * 0.25)
def extrusion_for_length(length):
return extrusion_volume_to_length(length * extrusion_width * layer_height)
def up():
global curr_z
curr_z += layer_height
print("G1 Z%.3f" % curr_z)
def line(x,y,speed):
length = sqrt(x**2 + y**2)
global curr_x, curr_y
curr_x += x
curr_y += y
if speed > 0:
print("G1 X%.3f Y%.3f E%.4f F%.0f" % (curr_x, curr_y, extrusion_for_length(length), speed * 60))
else:
print("G1 X%.3f Y%.3f F%.0f" % (curr_x, curr_y, travel_speed * 60))
def goto(x,y):
global curr_x, curr_y
curr_x = x + offset_x
curr_y = y + offset_y
print("G1 X%.3f Y%.3f" %(curr_x, curr_y))
# unused - maybe convert to a full bottom layer
def first_layer():
print_square(first_layer_speed)
goto(-object_width/2, )
def print_square(square_speed):
# start front center of cube
goto(0, - (object_width/2))
# line to front left corner
line(-object_width/2, 0, square_speed)
# line to back left corner
line(0, object_width, square_speed)
# line to back right corner
line(object_width, 0, square_speed)
# line to front right corner
line(0, -object_width, square_speed)
# line to start corner - extrusion width
line(-object_width/2 + extrusion_width, 0, square_speed)
def main():
pressure_advance = 0
print("; layer %d, pressure advance: %.3f" %(0, pressure_advance))
print("M572 D0 S%.3f" % pressure_advance)
# prime nozzle
print("G1 X%.3f Y%.3f Z%.3f E1.0 F%.0f" % (curr_x, curr_y, curr_z, travel_speed * 60))
print_square(first_layer_speed)
up()
for l in range(layers - 1):
if l != 0 and l % layer_multiple == 0 :
pressure_advance += pressure_advance_step
print("; layer %d, pressure advance: %.3f" %(l, pressure_advance))
print("M291 P\"Current K: %.3f\"" % pressure_advance)
print("M572 D0 S%.3f" % pressure_advance)
print_square(speed)
up()
print('; END.gcode\n\
G91 ; relative\n\
G1 Z10 F450 ; bed clearance\n\
G90 ; absolute\n\
M106 S0 ; turn off part cooling fan\n\
M104 S0 ; turn off extruder\n\
M140 S0 ; turn off bed\n\
M84 ; disable motors\n')
if __name__ == '__main__':
main()
The main thing I'm worried about is the end of the square. I print up to the start of the square minus the extrusion width and then raise the head the layer height. This has resulted in a bump in my print but that might be because of not enough PA.
