Under extrusion

[zungara 9]

After days of good printing i have got a problem with under extrusion which i got not solved.

 

I am printing a kind a table for my orchid. For one plant it was 2 pieces with a print time of 24 hours per piece. This was the good result:

 

 

 

I have sliced it with Cura with following settings:

 

filament_diameter = 2.82

nozzle_size = 0.4

wall_thickness = 0.8

retraction_enable = True

max_z_speed = 3.0

travel_speed = 150

layer_height = 0,2

solid_layer_thickness = 1

fill_density = 30

print_speed = 50

print_temperature = 210

support = None

enable_raft = False

filament_density = 1.00

skirt_line_count = 2

skirt_gap = 3.0

retraction_min_travel = 5.0

retraction_speed = 40.0

retraction_amount = 4.5

retraction_extra = 0.0

bottom_layer_speed = 20

cool_min_layer_time = 60

fan_enabled = True

bottom_thickness = 0

object_sink = 0.0

enable_skin = True

plugin_config = (lp1

.

model_matrix = 1.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,1.0

extra_base_wall_thickness = 0.0

cool_min_feedrate = 10

fan_layer = 1

fan_speed = 100

fan_speed_max = 100

raft_margin = 5

raft_base_material_amount = 100

raft_interface_material_amount = 100

support_rate = 25

support_distance = 0.3

infill_type = Grid Hexagonal

solid_top = True

fill_overlap = 20

bridge_speed = 100

sequence = Loops > Perimeter > Infill

force_first_layer_sequence = True

joris = False

retract_on_jumps_only = True

hop_on_move = False

 

For the second plant i want to print same again. So i used the gcode files again. But in the night problems began. I have marked it in the picture.

 

 

When i stand up the printer prints hours in the air.

 

I try it again but now i see in the beginning of the print the problem of under extrusion. I though i have a plugging problem and so i clean my hot end, but after rebuild the same behavior. I try to raise the temperature and to slow down the speed. The result are always the same. See the two mark in the picture. When i am looking on the print it seems to be a interval between good and bad extrusion.

 

 

If i have to print a short line (markt region) the region of under extrusion is about 10mm hight and of good extrusion is 16 mm hight. When i compare good and bad regions it seems to be always the same quotient.

 

Has anybody i idea what happens?

 

[gr5 2,002]

I think you should try kisslicer.

 

[zungara 9]

Why, the first print was perfect. I used the same gcode-file, with same setting, same material......and the diameter of the filament was nearly the same.

 

[thingster 0]

Maybe a change in filament diameter. Have you measured the current diameter? Some filaments are from bad quality and change their diameter within the same spool, often more than 0.1 mm which definitely can have an effect to prints, sometimes leading to under-extrusion.

 

[zungara 9]

The diameter of my fillament i used in Cura is 2.82 mm. I measure 1m fillament. The real diameter of my fillament varies from 2.83 to 2.90 mm.

Could it be, that there is something destroyed after printing a lot of hours (perhaps 5 hours) in the air...

I have tryed to print a smal calibration pyramid. Same behavior...a small area the print is good and than a smaler area is bad.

 

[ronald 0]

Hello Zungara,

Had a similar problem with underextruding. The diameter of my filament was varying from 2.85 mm to 3.2 mm.

When you expect diameter changes you have to measure in more directions since sometimes you can have an oval shape.

Also when your extrusion is fully stopped and measure the diameter just before the feeder, the extrusion the problem might be already gone.

When my filament diameter becomes above 3.05 mm it does not fit through the owden tube anymore.

When the diameter rises above 3.20mm it is diffcult to get the filament out of the bowden tube.

It looks like a blockage in the hot end, but after taking it appart several times I never had a blockage with the V2 Hotend.

Instead of getting another filament supplier, I used a 4mm ID bowden tube instead of the supplied 1/8" ID tubing.

 

[zungara 9]

@Ronald: In the past i had the same problem with bad filament you described. But that was not my problem in this case. With the help of Sander from Ultimaker support i found my problem. After the long print the Teflon Insulator was a little bit deformed and this was the reason why the filament was not able to go through the teflon insulator without touching it.

After exchanging the teflon insulator my problem was solved. I was very supprised because it was very less touching the filament.

 

When my filament diameter becomes above 3.05 mm it does not fit through the owden tube anymore.

When the diameter rises above 3.20mm it is diffcult to get the filament out of the bowden tube.

It looks like a blockage in the hot end, but after taking it appart several times I never had a blockage with the V2 Hotend.

 

Some where in the Ultimaker description you will find that the filament should not have a diameter bigger than 3.1 mm. If the filament is bigger than 3.1 mm you will first get trouble with the brass pipe and than with the bowden tube.