Slic3r default extrusion width?

General Software
1

Hello,

I’m comparing gcode selected from profiles for 0.30 layer thickness and 0.40 layer thickness and something puzzles me.

I’m slicing the large herringbone gear. For 0.40 the code starts with this:

; generated by Slic3r 0.9.8 on 2013-07-06 at 03:16:28

; layer_height = 0.4
; perimeters = 3
; top_solid_layers = 2
; bottom_solid_layers = 2
; fill_density = 0.75
; perimeter_speed = 40
; infill_speed = 60
; travel_speed = 130
; scale = 1
; nozzle_diameter = 0.5
; filament_diameter = 2.89
; extrusion_multiplier = 1
; perimeters extrusion width = 0.53mm
; infill extrusion width = 0.53mm
; first layer extrusion width = 0.40mm

For 0.30 the code starts with this:

; generated by Slic3r 0.9.8 on 2013-07-06 at 03:30:46

; layer_height = 0.3
; perimeters = 3
; top_solid_layers = 2
; bottom_solid_layers = 2
; fill_density = 0.75
; perimeter_speed = 40
; infill_speed = 60
; travel_speed = 130
; scale = 1
; nozzle_diameter = 0.5
; filament_diameter = 2.89
; extrusion_multiplier = 1
; perimeters extrusion width = 0.70mm
; infill extrusion width = 0.70mm
; first layer extrusion width = 0.45mm

How come the extrusion width is fatter (0.70mm) for my 0.30 profile than for my 0.40 profile? When I compare with this gcode shouldn’t it be 0.36mm instead? :confused:

My config.ini:

# generated by Slic3r 0.9.8 on Sat Jul  6 03:44:58 2013
bed_size = 190,200
bed_temperature = 0
bottom_solid_layers = 2
bridge_fan_speed = 100
bridge_flow_ratio = 1
bridge_speed = 60
brim_width = 0
complete_objects = 0
cooling = 1
default_acceleration = 0
disable_fan_first_layers = 1
duplicate = 1
duplicate_distance = 6
duplicate_grid = 1,1
end_gcode = M104 S0 ; turn off nozzle temperature\nM140 S0 ; turn off bed temperature\nG28 X0  ; home X axis\nM84     ; disable motors
external_perimeter_speed = 100%
extra_perimeters = 1
extruder_clearance_height = 20
extruder_clearance_radius = 20
extruder_offset = 0x0
extrusion_axis = E
extrusion_multiplier = 1
extrusion_width = 0
fan_always_on = 0
fan_below_layer_time = 60
filament_diameter = 2.89
fill_angle = 45
fill_density = 0.75
fill_pattern = line
first_layer_bed_temperature = 0
first_layer_extrusion_width = 150%
first_layer_height = 100%
first_layer_speed = 100%
first_layer_temperature = 0
g0 = 0
gap_fill_speed = 40
gcode_arcs = 0
gcode_comments = 0
gcode_flavor = reprap
infill_acceleration = 0
infill_every_layers = 1
infill_extruder = 1
infill_extrusion_width = 0
infill_speed = 60
layer_gcode = 
layer_height = 0.3
max_fan_speed = 100
min_fan_speed = 35
min_print_speed = 10
min_skirt_length = 0
notes = 
nozzle_diameter = 0.5
only_retract_when_crossing_perimeters = 0
output_filename_format = [input_filename_base].gcode
perimeter_acceleration = 0
perimeter_extruder = 1
perimeter_extrusion_width = 0
perimeter_speed = 40
perimeters = 3
post_process = 
print_center = 95,100
randomize_start = 1
retract_before_travel = 2
retract_length = 1.2
retract_length_toolchange = 3
retract_lift = 0
retract_restart_extra = 0
retract_restart_extra_toolchange = 0
retract_speed = 25
rotate = 0
scale = 1
skirt_distance = 6
skirt_height = 1
skirts = 2
slowdown_below_layer_time = 8
small_perimeter_speed = 40
solid_fill_pattern = rectilinear
solid_infill_below_area = 70
solid_infill_every_layers = 0
solid_infill_speed = 60
start_gcode = G28 ; home all axes
support_material = 0
support_material_angle = 0
support_material_extruder = 1
support_material_extrusion_width = 0
support_material_pattern = rectilinear
support_material_spacing = 2.5
support_material_speed = 60
support_material_threshold = 45
temperature = 0
threads = 2
toolchange_gcode = 
top_solid_infill_speed = 60
top_solid_layers = 2
travel_speed = 130
use_relative_e_distances = 0
vibration_limit = 0
z_offset = 0

Thanks.

2

I updated Slic3r to 0.9.10b and cleared my old profile. It still produces a fatter extrusion width for a 0.30 thick layer (0.70mm) than for 0.40 (0.53mm).

Still puzzled by this but I’m printing one anyway (in Lulzbot green :smiley: ) to see how it goes.

3

isn’t that the way it is supposed to go?

if you are extruding the same layer thickness as your nozzle thickness, then the extrusion will be nearly a cylinder, with the same width as your nozzle (0.35mm wide for a 0.35mm layer thickness and nozzle).
and then if you squish that down to get a thinner layer you would be widening the extrusion thickness…wouldn’t you? Like squishing a cylinder flat.

seems to make sense.

4

I never thought of it that way. It would indeed make sense.

And I forgot the TAZ comes with a 0.35mm nozzle rather than a 0.50 like my AO-100. That would explain why the extrusion width in the g-code I linked was thinner (0.36mm).

Thanks.