在有 5 个挤出机的打印机上，第 4 和第 5 个挤出机在缩回 9mm 后重新启动时会留下一个大斑点。打印机使用需要长时间缩回以避免拉丝的鲍登挤出机。在挤出机 1、2 和 3 上使用相同的设置不会发生斑点。

斑点发生在擦拭打开或关闭以及工具更换缩回打开或关闭时。我认为这与撤回有关，因为无论其他设置如何，将撤回设置为 0 都会停止该问题。

这是在 Slic3r V1 RC1 上测试的。我附上了产生这种效果的配置：

由 Slic3r 1.0.0RC1 于 2013 年 12 月 20 日星期五 14:27:20 生成

avoid_crossing_perimeters = 1
bed_size = 280,220
bed_temperature = 0
bottom_solid_layers = 2
bridge_acceleration = 0
bridge_fan_speed = 100
bridge_flow_ratio = 1 bridge_speed
= 35
brim_width = 0
complete_objects = 0
cooling =
default_acceleration = 0
disable_fan_first_layers = 0
duplicate = 1
duplicate_distance = 6 ,
duplicate_grid = 1
end_gcode = G92 E0; 重置挤出机\nG1 E-5 F1000；缩回挤出机以防止最终串\nT0;\nM104 S0 ; 关闭温度\nT1;\nM104 S0 ; 关闭温度\nT2;\nM104 S0 ; 关闭温度\nT3;\nM104 S0 ; 关闭温度\nT4;\nM104 S0 ; 关闭温度\nM140 S0 ; 关闭加热打印床\nG28 X0 ; 原点 X 轴\nM84 ; 禁用电机
external_perimeter_speed = 35
external_perimeters_first = 0
extra_perimeters = 1
extruder_clearance_height = 20
extruder_clearance_radius = 20 extruder_offset =
0x0,66.60×0,2.16×29.45,66.60×31.45,33.49×26.68 extruder_axis = E1,multiplier
= E1 ,multiplier
,1
extrusion_width = 0
fan_always_on =
fan_below_layer_time = 60
filament_diameter = 1.7,1.7,1.7,1.7,1.7
fill_angle = 45
fill_density = .05
fill_pattern =
rectilinear first_layer_acceleration = 0
first_layer_bed_temperature = 0
first_layer_extrusion_width = 150%
first_layer_height = 0.3096
first_layer_speed = 20
first_layer_temperature = 0,0,0,0,0
g0 = 0
gap_fill_speed = 35
gcode_arcs = 0
gcode_comments = 1
gcode_flavor = reprap
infill_acceleration = 0
infill_every_layers = 1
infill_extruder = 5
infill_extrusion_width = 0
infill_first = 1
infill_only_where_needed =
infill_speed = 35
layer_gcode =
layer_height = 0.3096
max_fan_speed = 100
min_fan_speed = 100
min_print_speed = 10
min_skirt_length = 10
notes =
nozzle_diameter = .35,.35,.35,.35,.35
only_retract_when_crossing_perimeters = 1 ooze_prevention
= 1
output_filename_format = Gcode_Verbose_Output = 1gcode
overhang perimeter_extruder = 5 perimeter_extrusion_width = 0 perimeter_speed = 35 perimeters = 2 post_process = print_center = 100,130 raft_layers = 0 randomize_start = resolution = 0 retract_before_travel = 3,3,3,3,3 retract_layer_change = 0,0,0,0,0

retract_length = 9,9,9,9,9
retract_length_toolchange = 9,9,9,9,9
retract_lift = 0,0,0,0,0
retract_restart_extra = 0,0,0,0,0
retract_restart_extra_toolchange = 0,0, 0,0,0
retract_speed = 5,5,5,5,5
rotate = 0
scale = 1
skirt_distance = 6
skirt_height = 1 skirts =
2 slowdown_below_layer_time
= 30
small_perimeter_speed = 35
solid_fill_pattern =
rectilinear solid_infill_below_area = 1
solid_infill_every_layers = 0
solid_infill_extrusion_width = 0
solid_infill_speed = 20
spiral_vase =
standby_temperature_delta = -20
start_gcode = M106 S255; 打开风扇\nG28 ; 归位所有轴\nT4；//set the 1st extruder to be active
start_perimeters_at_concave_points = 0
start_perimeters_at_non_overhang = 0
support_material =
support_material_angle = 0
support_material_enforce_layers = 0
support_material_extruder = 5
support_material_extrusion_width = 0
support_material_interface_extruder = 5
support_material_interface_layers = 1
support_material_interface_spacing = 2.5
support_material_pattern =
rectilinear support_material_spacing = 2.5
support_material_speed = 35
support_material_threshold = 0
温度 = 0,0,0,0,0
thin_walls = 1
线程 = 4
toolchange_gcode =
top_infill_extrusion_width = 0
top_solid_infill_speed = 20
top_solid_layers = 2
travel_speed = 60
use_firmware_retraction = 0
use_relative_e_distances = 0
vibration_limit = 0
wipe = 1,1,1,1,1
z_offset = 0