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xeo

Strange 'dots' on print

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Hello everyone,

I am new to this forum and new to the Ultimaker.

So far I am liking the machine pretty much :mrgreen:

There is one strange thing though in some of my prints that I actually have no idea where to find a solution for this. I am hoping one of you can help me out :oops:

I have attached a picture of the problem. (I tried at least)

It only seem to happen at rounded surfaces as I printed a fairly large squared box and it came out perfectly fine. The rest of the print is also fine.

If someone has a solution I will be happy to read :mrgreen:

Thanks in advance!!

Chris

problem.jpg

 

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I always thought that had to do with too much plastic being extruded during a 100% infill setting, the extra plastic has to go somewhere.

Try one or more of these:

 

  • increase the "filament diameter" setting
  • reduce the "Fill density percentage"
  • reduce the "Filament flow percentage"

 

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I always thought that had to do with too much plastic being extruded during a 100% infill setting, the extra plastic has to go somewhere.

Try one or more of these:

 

  • increase the "filament diameter" setting

  • reduce the "Fill density percentage"

  • reduce the "Filament flow percentage"

 

 

Thanks for your reply Anthony!

I'll give it a try and see what's happening when changing these values especially for the flow.

Strange thing still is that I printed the Ultimaker robot (see attached) and there I don't see any problems.

Only thing changed is layers of 0,06 instead of 0,25 mm rest of the settings identically.

As soon as I have tried the things you mentioned I will get back with hopefully positive details.

Thanks,

Chris

umrobot.jpg

 

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In my experience with cylinders this is a fairly common occurrence with Cura. You need to do one of two things; print real slow - no faster than 30, 20 is preferable. Or do it with Slic3r. If you watch the print real close you will see why it is happening. For whatever reason it does not happen with Slic3r, at least to anything like the same extent.

 

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Thanks for all replys.

I have tried what Anthony mentioned and see small differences in print result but the problem still occurs.

What Yellowshark is mentioning is actually what I think is happening. It looks like the weird dots are sort of starting points of each layer. It prints until that point and than continues the other way around. Is slicing it with Slic3r the only way to fix this?

What happens if you guys would print this? I can share the STL file if anyone of you is willing to give it a try ...

The product is a battery box so you could use it yourself :-P

Thanks,

Chris

 

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Those dot's really looks like starting points of a new layer.

Another possible cause can be that the nozzle temp is too high for the settings you have set.

 

It seems odd that the new layers start at such random location in the original image.

Anyway, I tried the file that XeO/Chris sent me and with my settings (mainly 50% infill I think is the key) there were no blobs. But the seam is definitely showing. Turn retraction on/off puts the seams in different places.

sml_gallery_17281_1329_16845.jpgsml_gallery_17281_1329_23267.jpg

I could not find a way to "attach" a text file in this forum so here is my .ini file:

[profile]

layer_height = 0.25

wall_thickness = 0.8

retraction_enable = False

solid_layer_thickness = 0.6

fill_density = 50

nozzle_size = 0.4

print_speed = 60

print_temperature = 225

print_temperature2 = 0

print_temperature3 = 0

print_temperature4 = 0

print_bed_temperature = 70

support = None

platform_adhesion = None

support_dual_extrusion = Both

wipe_tower = False

wipe_tower_volume = 15

ooze_shield = False

filament_diameter = 2.85

filament_diameter2 = 0

filament_diameter3 = 0

filament_diameter4 = 0

filament_flow = 100.0

retraction_speed = 40.0

retraction_amount = 4.5

retraction_dual_amount = 16.5

retraction_min_travel = 1.5

retraction_combing = True

retraction_minimal_extrusion = 0.02

retraction_hop = 0.0

bottom_thickness = 0.3

object_sink = 0.0

overlap_dual = 0.15

travel_speed = 150.0

bottom_layer_speed = 20

infill_speed = 0.0

inset0_speed = 0.0

insetx_speed = 0.0

cool_min_layer_time = 5

fan_enabled = True

skirt_line_count = 1

skirt_gap = 3.0

skirt_minimal_length = 150.0

fan_full_height = 0.5

fan_speed = 100

fan_speed_max = 100

cool_min_feedrate = 10

cool_head_lift = False

solid_top = True

solid_bottom = True

fill_overlap = 20

support_type = Grid

support_angle = 60

support_fill_rate = 15

support_xy_distance = 0.7

support_z_distance = 0.15

spiralize = False

brim_line_count = 20

raft_margin = 5

raft_line_spacing = 1.0

raft_base_thickness = 0.3

raft_base_linewidth = 0.7

raft_interface_thickness = 0.2

raft_interface_linewidth = 0.2

raft_airgap = 0.22

raft_surface_layers = 2

fix_horrible_union_all_type_a = False

fix_horrible_union_all_type_b = False

fix_horrible_use_open_bits = False

fix_horrible_extensive_stitching = False

plugin_config =

object_center_x = -1

object_center_y = -1

 

[alterations]

start.gcode = ;Sliced at: {day} {date} {time}

;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}

;Print time: {print_time}

;Filament used: {filament_amount}m {filament_weight}g

;Filament cost: {filament_cost}

G21 ;metric values

G90 ;absolute positioning

M107 ;start with the fan off

G28 X0 Y0 ;move X/Y to min endstops

G28 Z0 ;move Z to min endstops

G1 Z15.0 F{travel_speed} ;move the platform down 15mm

G92 E0 ;zero the extruded length

;G1 F200 E3 ;extrude 3mm of feed stock

G1 E20 F300 ;E__mm at F___mm/s

G92 E0 ;zero the extruded length again

G1 F{travel_speed}

;M301 P15.40 I0.70 D85.31 C1.0

M117 Printing...

end.gcode = ;End GCode

M104 S0 ;extruder heater off

M140 S0 ;heated bed heater off (if you have it)

G91 ;relative positioning

G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure

G1 Z+0.5 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more

G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way

M84 ;steppers off

G90 ;absolute positioning

start2.gcode = ;Sliced at: {day} {date} {time}

;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}

;Print time: {print_time}

;Filament used: {filament_amount}m {filament_weight}g

;Filament cost: {filament_cost}

G21 ;metric values

G90 ;absolute positioning

M107 ;start with the fan off

G28 X0 Y0 ;move X/Y to min endstops

G28 Z0 ;move Z to min endstops

G1 Z15.0 F{travel_speed} ;move the platform down 15mm

T1

G92 E0 ;zero the extruded length

G1 F200 E10 ;extrude 10mm of feed stock

G92 E0 ;zero the extruded length again

G1 F200 E-{retraction_dual_amount}

T0

G92 E0 ;zero the extruded length

G1 F200 E10 ;extrude 10mm of feed stock

G92 E0 ;zero the extruded length again

G1 F{travel_speed}

M117 Printing...

end2.gcode = ;End GCode

M104 T0 S0 ;extruder heater off

M104 T1 S0 ;extruder heater off

M140 S0 ;heated bed heater off (if you have it)

G91 ;relative positioning

G1 E-1 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure

G1 Z+0.5 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more

G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way

M84 ;steppers off

G90 ;absolute positioning

support_start.gcode =

support_end.gcode =

cool_start.gcode =

cool_end.gcode =

replace.csv =

switchextruder.gcode = ;Switch between the current extruder and the next extruder, when printing with multiple extruders.

G92 E0

G1 E-36 F5000

G92 E0

T{extruder}

G1 X{new_x} Y{new_y} Z{new_z} F{travel_speed}

G1 E36 F5000

G92 E0

 

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Hi Anthony,

I see in your pictures that you have the exact same issue?

Does the infill percentage really have something to do with this problem? When I am printing it it just puts two layers next to each other continuing with the next layer and so on. What I mean is that I don't see any infill happening ...

 

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It seems odd that the new layers start at such random location in the original image.

 

That is a standard feature of Cura, in the older version this was called "Joris Plugin".

Is is to prevent a visible scar when a new layer starts at the exact same point as the previous one.

 

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That is a standard feature of Cura, in the older version this was called "Joris Plugin".

Is is to prevent a visible scar when a new layer starts at the exact same point as the previous one.

 

Thanks. I understand now.

 

Hi Anthony,

I see in your pictures that you have the exact same issue?

Does the infill percentage really have something to do with this problem? When I am printing it it just puts two layers next to each other continuing with the next layer and so on. What I mean is that I don't see any infill happening ...

 

I guess the infill does not affect those bumps. I put it back at 100% infill and could not get the bumps that you had. I also reduced the filament diameter setting from 2.85 to 2.50 and the only effect was to have a much thicker object.

I am using Cura 10.04-RC1.

I am not sure that I can help you but am glad that you got rid of the bumps / nodules. Can you share with us the exact changes you made to your settings? I also noticed you used a different colour plastic ... that might be a factor also.

 

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Hi Anthony,

I have no idea how to post settings of Cura.

But the main settings I used in the last picture are:

* Filament diameter 2,95 mm

* Overall speed 20 mm

* Layer height 0,25

* Infill percentage 20%

* Material flow 100%

* Standard retraction settings

* Rest of settings standard Ultimaker 2 profile

My Cura version is 14.07

 

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