hi everybody,
I need to stress my Kossel, to evidence a problem it often does : sometime, likely after much working, a layer 'slides' a bit, the work goes on, and then (or not) it 'slides' again in opposite verse and the solid return regular; almost everytime the defect is very little, but it exists; so, I have to 'stress' my Kossel to investigate about he real cause, I had several thoughtes :
- a4988 chips too much warming? ( I used a fan to cool them, but I remove it now to evidence the defect, if it is the cause)
- I didn't set any type of acceleration, and I don't know in this case how acceleration is managed; anyhow, I left the default value in firmware (MAX 9000)
- too much current in a4988 ? I set it to 1.8 A (the chips has thir little dissipator mounted on), using Wantai motors , requiring up to 2.5 A for coil
to 'stress' the printer, I created a 'stress_profile', to increase the speed for creating the defect much possible as possible, here is the 'stress_profile' :
# generated by Slic3r 1.2.4 on Fri Jan 16 08:13:25 2015
avoid_crossing_perimeters = 1
bottom_solid_layers = 3
bridge_acceleration = 0
bridge_flow_ratio = 1
bridge_speed = 100
brim_width = 0
complete_objects = 0
default_acceleration = 0
dont_support_bridges = 1
external_fill_pattern = rectilinear
external_perimeter_extrusion_width = 0
external_perimeter_speed = 70%
external_perimeters_first = 0
extra_perimeters = 1
extruder_clearance_height = 20
extruder_clearance_radius = 20
extrusion_width = 0
fill_angle = 45
fill_density = 15%
fill_pattern = rectilinear
first_layer_acceleration = 0
first_layer_extrusion_width = 200%
first_layer_height = 100%
first_layer_speed = 70%
gap_fill_speed = 20
gcode_comments = 0
infill_acceleration = 0
infill_every_layers = 1
infill_extruder = 1
infill_extrusion_width = 0
infill_first = 0
infill_only_where_needed = 0
infill_speed = 200
interface_shells = 0
layer_height = 0.3
min_skirt_length = 0
notes =
only_retract_when_crossing_perimeters = 1
ooze_prevention = 0
output_filename_format = [input_filename_base].gcode
overhangs = 1
perimeter_acceleration = 0
perimeter_extruder = 1
perimeter_extrusion_width = 150%
perimeter_speed = 200
perimeters = 2
post_process =
raft_layers = 0
resolution = 0
seam_position = random
skirt_distance = 10
skirt_height = 1
skirts = 8
small_perimeter_speed = 70%
solid_infill_below_area = 70
solid_infill_every_layers = 10
solid_infill_extruder = 1
solid_infill_extrusion_width = 0
solid_infill_speed = 100%
spiral_vase = 0
standby_temperature_delta = -5
support_material = 0
support_material_angle = 0
support_material_enforce_layers = 0
support_material_extruder = 1
support_material_extrusion_width = 0
support_material_interface_extruder = 1
support_material_interface_layers = 3
support_material_interface_spacing = 0
support_material_interface_speed = 100%
support_material_pattern = pillars
support_material_spacing = 2.5
support_material_speed = 150t
support_material_threshold = 0
thin_walls = 1
threads = 2
top_infill_extrusion_width = 200%
top_solid_infill_speed = 70%
top_solid_layers = 3
travel_speed = 200
xy_size_compensation = 0
I set infill to 200 mm/sec, and solid infill too (100%); I set three horizontal shells at bottom and top, but, while the first three layer goes fast, since fourth layer, it goes down, doesn't proceed to same speed as I expect; I don't know what are missing or where I'm confuse
any help appreciated
regards