Weird printing issue - X shifted problem

Hello everyone,

I am having a little problem since I installed the servo based auto bed leveling.

When I try to print a piece it seems that it is shifted a little on the right on x axis and the piece is printed on the surrounding cleaning trace.

Here is a picture to explain



You can see that the left line of the piece itself is good (cleaning trace and piece trace are distinct) on left but on right it is mingled with the cleaning trace.
The piece is : [www.thingiverse.com]

It seems that the auto bed levelling settings cause this but I don't know what settings.

It happens on large piece but not on small ones.

Do you have any idea what can cause this ?

Thank you in advance for reading and for your help.

Madz

Edited 2 time(s). Last edit at 11/22/2015 05:31PM by madcreator.

It could be the glass is concave or domed, it could be the auto bed leveling sensor, servo arm or servo shake giving inaccurate readings, could be the y carriage that flexes under the probing.

Try repeating G30 manually, repeat it 10 times, what are the min, max and average values. Are they within 0.1mm? I've got a repeatability of 0.025mm deviation.

also turn on the log panel in repetier host and repeat g29 a few times, note down the values in a grid and compare them. If they are more than 0.3mm apart you might want to get the bed a bit more level to within 0.2mm deviation, I've managed 0.15 deviation from corner to corner after fixing a long list of problems.

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Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]

hi,

Thank you for you aswer !

I am gonna mae te different test that you suggest and return the results !

If I am not wrong, I need to do a G28 before a G29 command, right ? (just to be sure)

I am also gonna check the servo.

Madz

That's right, G28 before G29.

---

--
Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]

These are my value after several G30 : [1,38 | 1,44 | 1,29 | 1,40 | 1,29 | 1,38 | etc], not so bad but can be better.

My setup is kind of bad, so I think i am gonna rethink it ! But I wanted this kind of system because I had really really hard time to print something with hand-levelling..
I think the first problem is that I am using a switch with a metal contact : This kind of this one, i am gonna get rid of the metal contact so that only the switch is touching at 90°.

But I don't understand, the bed levelling only correct Z axis, don't it ? I see that the bed levelling is doing right (even with these not so good probing values) but the problem is on the X axis, and it isn't corrected by the auto bed levelling ?!


Thanks again for your time ! It Helps a lot !

Edited 1 time(s). Last edit at 11/25/2015 04:39PM by madcreator.

That's not bad, yep, I'd remove the metal thing, makes it more consistent. Auto bed leveling only corrects the angle of the bed and assumes it's entirely flat. It probes the bed and fits the best fitting triangle and takes the normal of it as the angle. It then translates x, y and z to place the object in that angle. It doesn't compensate a bent, concave, waving, domed etc bed.

Take a straight edge and put it's side on the bed, see if it's really flat. If your heated bed pcb is bent, as it often is, clamping a plate on it that's too thin will conform to the bent pcb to some degree. Also, if the pcb is screwed too tightly it will bend. Heating the bed may warp it differently than at room temperature. After 10-100 heat up/cooldowns it may conform to the glass plate at some point. I also bent it somewhat to make it more flat.

Also check if the x carriage is tightly fixed without play, the bearings are greased. Don't use oil as that will dissolve the grease inside and make it loosen up. Sometimes the hole for the z nut binds to the threaded rod lifting one side up, which results in unevenness in the xz direction.

---

--
Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]

Now it seems the problem also appear whenever I use the auto bed level or not.

It happens on this kind of large piece : [www.youmagine.com]

The first outter square is printed onto the cleaning trace (brim).

It seems that the problem is about large piece that doesn't fit on my print bed and that are scaled to fit in...

My print bed is 200x200mm so it's quite large.

It also happens on the front cover of this set of pieces : [www.thingiverse.com]

I don't know why...

Do you have any ideas ?

PS : this kind of piece prints very well without the above problem : [www.thingiverse.com]

Edited 1 time(s). Last edit at 11/29/2015 12:28PM by madcreator.

Maybe the x axis is binding sometimes, or the motor looses steps, did you try adjusting motor current? Make sure the smooth rods are well greased.

Try a smaller but much higher object placed close to either 0 or 200mm, see at what point it binds or shifts, maybe it will do this at higher layers too. Also make sure the print doesn't hit the end stop, that could cause a shift as well. If the gcode tries to go to x-10 and hits the endstop at x0 it still thinks it has reached x-10.

---

--
Kind regards
Imqqmi

NFAN CoreXY printer:
[reprap.org]

Hi,

After some test I think the problem comes from printer settings in repetier or slic3r because I created an stl of a 180mm×180mm square (m'y bed size is 200×200) and the size of the printed piece is downscaled...

Even if there is a little binding, I don't think (in my opinion only) that the problem is coming from settings but don't know where.... Or also maybe it can be coordinates errors (absolutes, etc...) ?

I tried printing near edge little pieces and everything is fine.

Thanks for your help.

Nothing should be downscaled in the slicer.
Maybe the STL was no good? Keep in mind that STL files won't store dimensions, that is why so many parts you find online will be of different size when importing them into Sketchup for example.
Did you actually confirm the head is moving 10cm when you send a 10cm move?

The STL was ok, I tried with this one and it printed badly like this (don't take account of the Z height problem).

Yes, I confirm, when I move the X axis of 100 mm, it is really 100 mm measured !

Edit : If it can help, here is the G-Code 3D rendering : Here

And also the G-code associated :

; generated by Slic3r 1.2.9 on 2015-12-04 at 18:47:57

; external perimeters extrusion width = 0.40mm
; perimeters extrusion width = 0.67mm
; infill extrusion width = 0.67mm
; solid infill extrusion width = 0.67mm
; top infill extrusion width = 0.67mm

M190 S70 ; set bed temperature
M104 S215 ; set temperature

M109 S215 ; wait for temperature to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0
M106 S255
G1 E-1.00000 F1800.00000
G92 E0
G1 Z0.400 F9000.000
G1 X20.471 Y20.115 F9000.000
G1 E1.00000 F1800.00000
G1 X22.116 Y19.173 E1.16210 F1800.000
G1 X23.500 Y18.958 E1.28183
G1 X176.500 Y18.958 E14.36410
G1 X178.354 Y19.353 E14.52620
G1 X179.885 Y20.471 E14.68830 F1800.000
G1 X180.827 Y22.116 E14.85039
G1 X181.042 Y23.500 E14.97012
G1 X181.042 Y176.500 E28.05239
G1 X180.647 Y178.354 E28.21449
G1 X179.529 Y179.885 E28.37659
G1 X177.884 Y180.827 E28.53869
G1 X176.500 Y181.042 E28.65842
G1 X23.500 Y181.042 E41.74069
G1 X21.646 Y180.647 E41.90279
G1 X20.115 Y179.529 E42.06489
G1 X19.173 Y177.884 E42.22699
G1 X18.958 Y176.500 E42.34672
G1 X18.958 Y23.500 E55.42899
G1 X19.353 Y21.646 E55.59108
G1 X20.436 Y20.163 E55.74805
G1 X20.901 Y20.455 F9000.000
G1 X20.974 Y20.362 E55.75822 F1800.000
G1 X22.577 Y19.579 E55.91076
G1 X23.500 Y19.472 E55.99019
G1 X176.500 Y19.472 E69.07246
G1 X178.240 Y19.867 E69.22500
G1 X179.638 Y20.974 E69.37754 F1800.000
G1 X180.421 Y22.577 E69.53008
G1 X180.528 Y23.500 E69.60950
G1 X180.528 Y176.500 E82.69177
G1 X180.133 Y178.240 E82.84431
G1 X179.026 Y179.638 E82.99685
G1 X177.423 Y180.421 E83.14940
G1 X176.500 Y180.528 E83.22882
G1 X23.500 Y180.528 E96.31109
G1 X21.760 Y180.133 E96.46363
G1 X20.362 Y179.026 E96.61617
G1 X19.579 Y177.423 E96.76871
G1 X19.472 Y176.500 E96.84813
G1 X19.472 Y23.500 E109.93040
G1 X19.867 Y21.760 E110.08295
G1 X20.863 Y20.502 E110.22019
G1 X21.312 Y20.814 F9000.000
G1 X21.475 Y20.628 E110.24130 F1800.000
G1 X23.500 Y19.986 E110.42298
G1 X176.500 Y19.986 E123.50525
G1 X178.117 Y20.380 E123.64760
G1 X179.372 Y21.475 E123.78994 F1800.000
G1 X180.014 Y23.500 E123.97162
G1 X180.014 Y176.500 E137.05389
G1 X179.620 Y178.117 E137.19624
G1 X178.525 Y179.372 E137.33858
G1 X176.500 Y180.014 E137.52026
G1 X23.500 Y180.014 E150.60254
G1 X21.883 Y179.620 E150.74488
G1 X20.628 Y178.525 E150.88722
G1 X19.986 Y176.500 E151.06891
G1 X19.986 Y23.500 E164.15118
G1 X20.380 Y21.883 E164.29352
G1 X21.273 Y20.859 E164.40962
G1 E163.40962 F1800.00000
G92 E0
G1 X23.181 Y22.729 F9000.000
G1 E1.00000 F1800.00000
G1 X176.819 Y22.729 E14.13690 F1800.000
G1 X177.271 Y23.181 E14.19153
G1 X177.271 Y176.819 E27.32843 F1800.000
G1 X176.819 Y177.271 E27.38306
G1 X23.181 Y177.271 E40.51996
G1 X22.729 Y176.819 E40.57459
G1 X22.729 Y23.181 E53.71150
G1 X23.138 Y22.771 E53.76100
G1 X23.243 Y23.394 F9000.000
G1 X23.394 Y23.243 E53.77921 F1800.000
G1 X176.606 Y23.243 E66.87969
G1 X176.757 Y23.394 E66.89790
G1 X176.757 Y176.606 E79.99838
G1 X176.606 Y176.757 E80.01659
G1 X23.394 Y176.757 E93.11707
G1 X23.243 Y176.606 E93.13528
G1 X23.243 Y23.454 E106.23063
G1 X23.800 Y23.800 F9000.000
G1 X176.200 Y23.800 E119.26160 F1080.000
G1 X176.200 Y176.200 E132.29256
G1 X23.800 Y176.200 E145.32353
G1 X23.800 Y23.860 E158.34937
G1 X24.146 Y24.000 F9000.000
G1 X24.200 Y24.200 F9000.000
G1 X175.800 Y24.200 E171.31193 F1080.000
G1 X175.800 Y175.800 E184.27449
G1 X24.200 Y175.800 E197.23706
G1 X24.200 Y24.260 E210.19449
G1 X24.200 Y23.800 F9000.000
G1 E209.19449 F1800.00000
G92 E0
G1 X28.950 Y28.950 F9000.000
G1 E1.00000 F1800.00000
G1 X171.050 Y28.950 E13.15027 F1080.000
G1 X171.050 Y171.050 E25.30053
G1 X28.950 Y171.050 E37.45080
G1 X28.950 Y29.010 E49.59593
G1 X29.296 Y29.150 F9000.000
G1 X29.350 Y29.350 F9000.000
G1 X170.650 Y29.350 E61.67779 F1080.000
G1 X170.650 Y170.650 E73.75966
G1 X29.350 Y170.650 E85.84152
G1 X29.350 Y29.410 E97.91825
G1 X29.350 Y28.950 F9000.000
G1 E96.91825 F1800.00000
G92 E0
G1 X34.100 Y34.100 F9000.000
G1 E1.00000 F1800.00000
G1 X165.900 Y34.100 E12.26956 F1080.000
G1 X165.900 Y165.900 E23.53913
G1 X34.100 Y165.900 E34.80869
G1 X34.100 Y34.160 E46.07312
G1 X34.446 Y34.300 F9000.000
G1 X34.500 Y34.500 F9000.000
G1 X165.500 Y34.500 E57.27428 F1080.000
G1 X165.500 Y165.500 E68.47544
G1 X34.500 Y165.500 E79.67660
G1 X34.500 Y34.560 E90.87263
G1 X34.500 Y34.100 F9000.000
G1 E89.87263 F1800.00000
G92 E0
M107
M104 S0 ; turn off temperature
G28 X0  ; home X axis
M84     ; disable motors

; filament used = 559.4mm (1.3cm3)

; avoid_crossing_perimeters = 0
; bed_shape = 0x0,200x0,200x200,0x200
; bed_temperature = 70
; before_layer_gcode = 
; bridge_acceleration = 0
; bridge_fan_speed = 100
; brim_width = 1
; complete_objects = 0
; cooling = 1
; default_acceleration = 0
; disable_fan_first_layers = 0
; duplicate_distance = 6
; end_gcode = M104 S0 ; turn off temperature\nG28 X0  ; home X axis\nM84     ; disable motors\n
; extruder_clearance_height = 20
; extruder_clearance_radius = 20
; extruder_offset = 0x0
; extrusion_axis = E
; extrusion_multiplier = 1
; fan_always_on = 1
; fan_below_layer_time = 60
; filament_colour = #000000
; filament_diameter = 1.75
; first_layer_acceleration = 0
; first_layer_bed_temperature = 70
; first_layer_extrusion_width = 150%
; first_layer_speed = 50%
; first_layer_temperature = 215
; gcode_arcs = 0
; gcode_comments = 0
; gcode_flavor = reprap
; infill_acceleration = 0
; infill_first = 0
; layer_gcode = 
; max_fan_speed = 100
; max_print_speed = 80
; max_volumetric_speed = 0
; min_fan_speed = 100
; min_print_speed = 10
; min_skirt_length = 0
; notes = 
; nozzle_diameter = 0.4
; only_retract_when_crossing_perimeters = 1
; ooze_prevention = 0
; output_filename_format = [input_filename_base].gcode
; perimeter_acceleration = 0
; post_process = 
; pressure_advance = 0
; resolution = 0
; retract_before_travel = 2
; retract_layer_change = 1
; retract_length = 1
; retract_length_toolchange = 10
; retract_lift = 0
; retract_restart_extra = 0
; retract_restart_extra_toolchange = 0
; retract_speed = 30
; skirt_distance = 3
; skirt_height = 1
; skirts = 3
; slowdown_below_layer_time = 30
; spiral_vase = 0
; standby_temperature_delta = -5
; start_gcode = 
; temperature = 210
; threads = 2
; toolchange_gcode = 
; travel_speed = 150
; use_firmware_retraction = 0
; use_relative_e_distances = 0
; use_volumetric_e = 0
; vibration_limit = 0
; wipe = 0
; z_offset = 0
; dont_support_bridges = 1
; extrusion_width = 0
; first_layer_height = 0.4
; infill_only_where_needed = 1
; interface_shells = 0
; layer_height = 0.2
; raft_layers = 0
; seam_position = aligned
; support_material = 0
; support_material_angle = 0
; support_material_contact_distance = 0.2
; 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 = 60
; support_material_threshold = 60
; xy_size_compensation = 0
; bottom_solid_layers = 3
; bridge_flow_ratio = 1
; bridge_speed = 60
; external_fill_pattern = rectilinear
; external_perimeter_extrusion_width = 0
; external_perimeter_speed = 90%
; external_perimeters_first = 0
; extra_perimeters = 1
; fill_angle = 45
; fill_density = 15%
; fill_pattern = rectilinear
; gap_fill_speed = 35
; infill_every_layers = 1
; infill_extruder = 1
; infill_extrusion_width = 0
; infill_overlap = 15%
; infill_speed = 50
; overhangs = 1
; perimeter_extruder = 1
; perimeter_extrusion_width = 0
; perimeter_speed = 40
; perimeters = 2
; small_perimeter_speed = 40
; solid_infill_below_area = 70
; solid_infill_every_layers = 0
; solid_infill_extruder = 1
; solid_infill_extrusion_width = 0
; solid_infill_speed = 45
; thin_walls = 1
; top_infill_extrusion_width = 0
; top_solid_infill_speed = 45
; top_solid_layers = 3

Edited 2 time(s). Last edit at 12/04/2015 02:07PM by madcreator.

Hi again !

I understand what is going on but can't manage to find how to fix it.

If the pieces are printed 20 mm from the right edge, the printer thinks it's the printing bed limit and juste prints layer according to this limit (without going past).

I just check the printer settings in repetier and slic3r and they are correct (200mmx200mm printing area). For me the limit appears to be at 165 mm in X and Y but I can't find why...

Thanks,

Madcreator

Looks like the classic un-flat bed. You may want to hone the surface with block and fine sand paper.

I don't understand why an un-flat bed can cause X shift, and also I can't sand the print bed because it glass.