Taz 4 first layer issues

Hello all,
I have been having some 1st layer ABS issues on my new Taz 4. To help identify the problem i’ve attached a photo to this post as well.

From what i can tell the layers go down smooth until the nozzle reverses direction. When it pauses momentarily to reverse (despite the extruder momentarily reversing to prevent oozing) it continues to flow causing ABS to bunch up at every point the nozzle reverses direction.

Thus far I have tried:
-Adjusting my extrusion temperature up and down from 230 C +/-15 (No effect)
-Changing my slicer to extrude a thinner first layer (Changed first layer extrusion width with no effect although holes are more accurately created)
-Raising nozzle further from bed (Resulted in poor adhesion) (Closer to the bed problem becomes worse and it drags along glass)
-Verified my extrusion amount (Set slicer to extrude 100mm and 100mm is extruded)
-Adjusted my extrusion multiplier so that extruded walls measure to be exactly as indicated in the G-code.

From the picture i don’t believe the bed is not leveled because if it was not level at some locations the outer perimeters would have been messed up. However i could be wrong in this assumption.

I have not modified my print speed substantially due to the fact that i believe slower would significantly increase the issue?

If i design a print file where the nozzle makes 0 direction reversals I have a clean print.

Overall if i let the problem continue and it doesn’t tear itself apart during the 1st layer, on subsequent passes the nozzle would ram the built up material and obviously this is not an intended function of a normal print.

Any assistance with the problem would be greatly appreciated and thank you in advance to everybody for taking time to help.
taz 4 problem.jpg

Ever type a really long reply to a post and then accuidentally hit the back button and lose all that text? It’s really annoying when that happens.

Anyways, long drawn out post short, It looks like you might have some tape residue in the upper right hand corner of that PEI sheet you are printing on where the torn up area is happening, clean it with rubbing alchohol, also it looks like your extrusion is having some issues. I went into a long details description here about that, but basically you may have some debris in your hobbed bolt ridges, and the spring tension looks to be a little light and you should probably tighten it and you want to go with a thicker starting layer, not a thinner one. A thicker starting layer will tend to make the ABS adhere better to the PEI.

You may also want to increase the bed temperature to 87. You may also want to check your filliament diameter measurement in your slic3r profile, and possibly re-do your extruder calibration using a slower extrusion to make sure it is dead on.

The pooling in the corners on reverse is somewhat normal. There are some controllers out there that take that motion into account better (such as the tinyG controller) but basically it’s the liquid plastic equivelent of water sloshing in a bucket during a sharp turn. Having your calibration dead on will minimize that, and the starting layer being thicker will help, but you should also expect to see a little of that at perimeter edges.

Hope that helps

Are you running one of the standard ABS profiles from Lulzbot?
What’s your bed temp setting?
What are you using on your bed for a “glue”? Lulzjuice? (I assume that’s a PEI bed surface.)
Have you run the Lulzbot provided bed level calibration?
You can find it here: http://download.lulzbot.com/TAZ/4.0/calibration/bed_calibration.gcode
What’s your fan doing during your print?

I’ve done the accidental back button many times unfortunately.

The residue on the glass is actually a water soluble glue stick that was used to help the abs adhesion to the bed. Without it some parts come off and others don’t.

With regards to the extrusion i double checked the hobbed bolt ridges and filament spring tension. The filament had slight teeth marks from the extruder on it so I re-adjusted the tension upon re-insertion.

Bed Temp was 100 C for both tests. with a picture of test # 2 attached. It was not run on one of the standard ABS profiles. I have tried them it just didn’t seem to be any better. Yes the standard bed level cal was run initially when i received the bed however as i no longer use the 12X12 sheet that covers the whole bed it was hard to tell level vice just a bump over the kaplon tape. Fan is off for all first layers as well.

Test #2 seems closer:
Has smoother reversals and not as much clumping on turns.
The center ring is showing up but the overall rings seem to increase / decrease in thickness as the head moves. tightening the springs will probably help that?

This time around It looks like the nozzle may be too close to the bed as It has a little bit of lines running between the concentric rings where ooze may have gotten out.

Ultimately the print jammed up on the left side of the bed this time vice the right. strange with no level change how that could have happened.
Taz test 2.jpg

Well, It would appear the glue stick was partially to blame. Despite it feeling smooth to the touch it obviously was not. I cleaned it off and ran the program from the SD card vice the computer and the attached picture was the result.

I didn’t notice any motor delays when it was run from the computer but its probably better to run off the sd card anyway.

Below are the settings for my successful test run for others who may be having a similar issue.

and thanks again to edlink and piercet for the suggestions.

; avoid_crossing_perimeters = 1
; bed_size = 298,275
; bed_temperature = 85
; bridge_acceleration = 0
; bridge_fan_speed = 100
; bridge_flow_ratio = 1.01
; brim_width = 0
; complete_objects = 0
; cooling = 0
; default_acceleration = 0
; disable_fan_first_layers = 1
; duplicate_distance = 6
; end_gcode = M104 S0 ; turn off extruder temperature\nM140 S0 ; turn off bed\nM107 ; turn off Extruder Fans\nG28 X0 Y0 ; home X axis Y axis\nG1 Y250 ; kick out bed\nM84 ; disable motors
; external_perimeters_first = 0
; extruder_clearance_height = 20
; extruder_clearance_radius = 20
; extruder_offset = 0x0
; extrusion_axis = E
; extrusion_multiplier = 0.95
; fan_always_on = 0
; fan_below_layer_time = 60
; filament_diameter = 3
; first_layer_acceleration = 0
; first_layer_bed_temperature = 85
; first_layer_extrusion_width = 0.5
; first_layer_speed = 50%
; first_layer_temperature = 230
; g0 = 0
; gcode_arcs = 0
; gcode_comments = 0
; gcode_flavor = reprap
; infill_acceleration = 0
; infill_first = 0
; layer_gcode =
; max_fan_speed = 100
; min_fan_speed = 35
; min_print_speed = 10
; min_skirt_length = 0
; notes =
; nozzle_diameter = 0.35
; only_retract_when_crossing_perimeters = 0
; ooze_prevention = 0
; output_filename_format = [input_filename_base].gcode
; perimeter_acceleration = 0
; post_process =
; print_center = 149,138
; resolution = 0.01
; retract_before_travel = 2
; retract_layer_change = 1
; retract_length = 2
; retract_length_toolchange = 10
; retract_lift = 0
; retract_restart_extra = 0
; retract_restart_extra_toolchange = 0
; retract_speed = 25
; skirt_distance = 6
; skirt_height = 1
; skirts = 2
; slowdown_below_layer_time = 30
; spiral_vase = 0
; standby_temperature_delta = -5
; start_gcode = G28 ; home all axes\nM203 X192 Y208 Z3 ; Speed limits to minimize skipped steps when moving really fast courtesy of forum.lulzbot.com user 1013
; temperature = 230
; threads = 2
; toolchange_gcode =
; travel_speed = 180
; use_firmware_retraction = 0
; use_relative_e_distances = 0
; vibration_limit = 0
; wipe = 0
; z_offset = 0
; dont_support_bridges = 1
; extrusion_width = 0.35
; first_layer_height = 0.3
; infill_only_where_needed = 0
; interface_shells = 0
; layer_height = 0.22
; raft_layers = 0
; seam_position = random
; 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 = honeycomb
; support_material_spacing = 5
; support_material_speed = 60
; support_material_threshold = 0
; bottom_solid_layers = 1
; bridge_speed = 40
; external_perimeter_speed = 80
; extra_perimeters = 0
; fill_angle = 45
; fill_density = 50%
; fill_pattern = rectilinear
; gap_fill_speed = 40
; infill_every_layers = 1
; infill_extruder = 1
; infill_extrusion_width = 0.5
; infill_speed = 115
; overhangs = 1
; perimeter_extruder = 1
; perimeter_extrusion_width = 0.33
; perimeter_speed = 100
; perimeters = 1
; small_perimeter_speed = 60
; solid_fill_pattern = rectilinear
; solid_infill_below_area = 70
; solid_infill_every_layers = 0
; solid_infill_extrusion_width = 0.38
; solid_infill_speed = 100
; thin_walls = 1
; top_infill_extrusion_width = 0.22
; top_solid_infill_speed = 70
; top_solid_layers = 1
Taz test 3.jpg

Just to clarify, are you printing on a sheet of PEI plastic, or are you printing directly on bare glass without some sort of plastic layer between it and the printed plastic? I can’t tell from the picture.

If you are printing on PEI, you should not need glue sticks at all.

I am printing on an 8" X 8" Polyimide Tape (Kapton Tape)

http://www.amazon.com/gp/product/B00MHXCQPK/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

When i was first printing on the bare plastic the parts were incredibly hard to remove and almost so much so that it would tear the tape. I still need to experiment with various levels of bed temperature to see if I can’t find a better temp to remove ABS.

I’ve never had a part pop off this tape regardless of part height or size. I’ve printed from a .5" wide 9" tall piece to a 1mm thick part that was 7" wide. All parts are printed with a 2mm wide brim for adhesion.