Odd print problem After a fully successful first android print I updated to the Neil Darlow fw and since only prints in one direction at the time turn out well (like the calibration angle). Bi-directional prints (base of a cube) keeps being printed at a slant. Motor current was turned down a bit before the android print but has not been touched since. Pulleys seem not to slip but still remains to be confirmed (and the angle still comes out fine). Are there any setting in the need of attention when switching from the nophead to the neil fw (like acceleration values)? Bed PID is currently active. https://reprap.org/forum/read.php?292,490857,490857#msg-490857 Wed, 09 Sep 2026 11:19:55 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?292,490857,536504#msg-536504 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,536504#msg-536504 09zx-6r Mendel90 Fri, 24 Jul 2015 00:27:19 -0400 https://reprap.org/forum/read.php?292,490857,536174#msg-536174 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,536174#msg-536174 nophead Mendel90 Thu, 23 Jul 2015 06:06:51 -0400 https://reprap.org/forum/read.php?292,490857,536117#msg-536117 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,536117#msg-536117
20150722_180656.jpg


and yes i know i have dirty hands, im a motorcycle tech and at work when photo'd...

thoughts?
]]> 09zx-6r Mendel90 Thu, 23 Jul 2015 03:02:53 -0400 https://reprap.org/forum/read.php?292,490857,533401#msg-533401 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,533401#msg-533401 When extruding 100 mm PLA at 185c exactly 100 mm goes in, single wall is at this point more or less spot on (0.5 mm in skeinforge and 0.55mm in real life which should be about right as no support is provided from adjacent paths).
Enclosed is a comparison top to bottom of prints with multiplier 0.94, 0.9 and 0.86 (entered inverted in skeinforge).
[attachment 58224 rps20150716_221956.jpg]

The top layer does not become smooth until a multiplier of 0.86, but this causes the perimeters to come apart. Also the over extrusion seem to appear mostly during acceleration.
I have tried lowering the temperature to 175c, below that the resistance was to great.
As the same phenomena appear in slic3r I would guess this might be filament/hardware/marlin related.
Any idea's what to test?]]> hsbontop Mendel90 Thu, 16 Jul 2015 16:29:55 -0400 https://reprap.org/forum/read.php?292,490857,512566#msg-512566 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,512566#msg-512566 hsbontop Mendel90 Sat, 23 May 2015 08:55:52 -0400 https://reprap.org/forum/read.php?292,490857,508132#msg-508132 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,508132#msg-508132 nophead Mendel90 Tue, 12 May 2015 10:07:20 -0400 https://reprap.org/forum/read.php?292,490857,508123#msg-508123 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,508123#msg-508123 [attachment 54534 rps20150512_151616.jpg]]]> hsbontop Mendel90 Tue, 12 May 2015 09:40:50 -0400 https://reprap.org/forum/read.php?292,490857,501136#msg-501136 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,501136#msg-501136
Quote
nophead
The retraction distance should be just enough to stop ooze on long travels. You can have the retract speed too fast though, so it doesn't have time to flow from the nozzle at the start.
My comment was mostly to acknowledge the speed mod actually made a difference, lowering the distance solved the problem but my blobs still appear. I have kept the high retraction speed as per recommendation from Neil.]]> hsbontop Mendel90 Fri, 24 Apr 2015 08:55:06 -0400 https://reprap.org/forum/read.php?292,490857,501135#msg-501135 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,501135#msg-501135
Quote
nophead
Is it overshoot, or is it too much plastic at the corner due to the axis slowing down and the filament flow rate lagging behind?
The second is my main theory as slowing down and deaccelerating does not solve the problem, I am a novice at gitfu but should this not be something that can be changed in the fw?]]> hsbontop Mendel90 Fri, 24 Apr 2015 08:52:48 -0400 https://reprap.org/forum/read.php?292,490857,501124#msg-501124 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,501124#msg-501124 nophead Mendel90 Fri, 24 Apr 2015 08:32:37 -0400 https://reprap.org/forum/read.php?292,490857,501113#msg-501113 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,501113#msg-501113 nophead Mendel90 Fri, 24 Apr 2015 08:16:12 -0400 https://reprap.org/forum/read.php?292,490857,501044#msg-501044 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,501044#msg-501044 hsbontop Mendel90 Fri, 24 Apr 2015 05:30:38 -0400 https://reprap.org/forum/read.php?292,490857,498257#msg-498257 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,498257#msg-498257 Another look at the original flow single wall print and this also had dimples not blobs. The infill prints has blobs so a new go with the infill print with the dimple setting is the next step.]]> hsbontop Mendel90 Fri, 17 Apr 2015 15:08:19 -0400 https://reprap.org/forum/read.php?292,490857,498043#msg-498043 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,498043#msg-498043
Also the faster you extrude, the higher the pressure needs to be at the end of the fast forward. As it ramps up from zero to that pressure the amount of material extruded on the spot should be just enough to make a cylinder with diameter equal to the width. That is constant regardless of speed so the for higher speeds the fast forward needs to faster to allow it to get to a higher pressure without extruding any more.]]> nophead Mendel90 Fri, 17 Apr 2015 07:44:51 -0400 https://reprap.org/forum/read.php?292,490857,497958#msg-497958 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497958#msg-497958 I'll have a look on replacing the extruder, but for now the quality is astonishing! The small blobs at the start of each layer is less of a problem in Slic3r.]]> hsbontop Mendel90 Fri, 17 Apr 2015 04:36:05 -0400 https://reprap.org/forum/read.php?292,490857,497846#msg-497846 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497846#msg-497846
In the previous post you said didn't have corner blobs with Slic3r?

The problem is due to the fact that you are using 1.75 filament in an extruder designed for 3mm. It needs to be fed three times faster with 1/3 of the force so you don't need the gears. With them your retraction speed is limited. A direct drive extruder is better with 1.75mm.

As I suspected there was a bug in Marlin that limits the maximum extruder acceleration that works properly to 3500, see [github.com]. I just fixed that and it does allow a faster retract but I also found the jerk setting for the extruder is ignored if the XY jerk is smaller I will fix that tomorrow and find some better retract settings that might help.]]> nophead Mendel90 Thu, 16 Apr 2015 19:20:34 -0400 https://reprap.org/forum/read.php?292,490857,497790#msg-497790 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497790#msg-497790 hsbontop Mendel90 Thu, 16 Apr 2015 17:02:10 -0400 https://reprap.org/forum/read.php?292,490857,497371#msg-497371 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497371#msg-497371 hsbontop Mendel90 Wed, 15 Apr 2015 16:15:34 -0400 https://reprap.org/forum/read.php?292,490857,497368#msg-497368 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497368#msg-497368 Noticed Slic3r was running absolute so this was changed to relative and a new print started at E501. Again massive overextrusion...

Thought of the Swedish decimal "," might confuse but I can see no errors in the GCODE generated.

; filament used = 133.7mm (0.3cm3)
; avoid_crossing_perimeters = 0
; bed_size = 200,200
; bed_temperature = 70
; bridge_acceleration = 0
; bridge_fan_speed = 100
; bridge_flow_ratio = 1
; brim_width = 0
; complete_objects = 0
; cooling = 1
; default_acceleration = 0
; disable_fan_first_layers = 1
; duplicate_distance = 6
; end_gcode = M104 S0 ; turn off extruder\nM140 S0 ; bed off\nM107 ; carriage fan off\nG1 X0 Y0 F9000 ; go to back\nG1 Z180 F9000 ; go to top\nM84 ; disable motors\n
; external_perimeters_first = 0
; extruder_clearance_height = 20
; extruder_clearance_radius = 20
; extruder_offset = 0x0
; extrusion_axis = E
; extrusion_multiplier = 1
; fan_always_on = 0
; fan_below_layer_time = 60
; filament_diameter = 1.74
; first_layer_acceleration = 0
; first_layer_bed_temperature = 70
; first_layer_extrusion_width = 200%
; first_layer_speed = 30%
; first_layer_temperature = 190
; 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 = 0.4
; only_retract_when_crossing_perimeters = 1
; ooze_prevention = 0
; output_filename_format = [input_filename_base].gcode
; perimeter_acceleration = 0
; post_process =
; print_center = 100,100
; resolution = 0
; retract_before_travel = 2
; retract_layer_change = 1
; retract_length = 0
; retract_length_toolchange = 10
; retract_lift = 0
; retract_restart_extra = 0
; retract_restart_extra_toolchange = 0
; retract_speed = 50
; skirt_distance = 6
; skirt_height = 1
; skirts = 1
; slowdown_below_layer_time = 30
; spiral_vase = 0
; standby_temperature_delta = -5
; start_gcode = M83 ; use relative distances for extrusion\nG28 ; home\nG1 X100 Y10 F9000 ; Go to the middle of the front\nG1 Z0.05 ; close to the bed\nM104 S185 ; set extruder temp\nM190 S70 ; set bed temp & wait\nM109 S185 ; wait for extruder temp\nG92 E0;\nG1 X50 E5 F200 ; make a thick line to prime extruder\nG1 E-1 F1200\nG1Z0.3 ;lift Z
; temperature = 185
; threads = 2
; toolchange_gcode =
; travel_speed = 130
; use_firmware_retraction = 0
; use_relative_e_distances = 1
; vibration_limit = 0
; wipe = 0
; z_offset = 0
; dont_support_bridges = 1
; extrusion_width = 0
; first_layer_height = 0.2
; infill_only_where_needed = 0
; interface_shells = 0
; layer_height = 0.2
; raft_layers = 0
; seam_position = aligned
; 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 = 60
; support_material_threshold = 0
; bottom_solid_layers = 3
; bridge_speed = 60
; external_perimeter_speed = 70%
; extra_perimeters = 1
; fill_angle = 45
; fill_density = 25%
; fill_pattern = honeycomb
; gap_fill_speed = 20
; infill_every_layers = 1
; infill_extruder = 1
; infill_extrusion_width = 0
; infill_speed = 60
; overhangs = 1
; perimeter_extruder = 1
; perimeter_extrusion_width = 0
; perimeter_speed = 30
; perimeters = 3
; small_perimeter_speed = 30
; solid_fill_pattern = rectilinear
; solid_infill_below_area = 70
; solid_infill_every_layers = 0
; solid_infill_extrusion_width = 0
; solid_infill_speed = 60
; thin_walls = 1
; top_infill_extrusion_width = 0
; top_solid_infill_speed = 50
; top_solid_layers = 3]]> hsbontop Mendel90 Wed, 15 Apr 2015 16:07:42 -0400 https://reprap.org/forum/read.php?292,490857,497326#msg-497326 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497326#msg-497326
If calibration by extruding 100mm of filament gives accurate feed then I can only conclude that the error is being introduced by slicer settings.

I think that regardless of whether you are using 1.75mm or 2.85mm filament, for an extruder calibrated using the 100mm of filament extrude method the different filament diameters should print the same provided the slicer is configured correctly (nophead will correct me if I am wrong).

I would check your slicer settings for a non-unity extrusion multiplier or flowrate multiplier. I cannot believe that for an identical input of filament an E3D hotend puts out more material than a J-Head.

One other possibility, I guess, is that your nozzle diameter is not accurate or is incorrectly set in the slicer. That would account for some discrepancy.

Regards,
Neil Darlow]]> neildarlow Mendel90 Wed, 15 Apr 2015 14:18:51 -0400 https://reprap.org/forum/read.php?292,490857,497319#msg-497319 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497319#msg-497319 Extruded 50 mm with original 100 mm calibrated setting and it came out at exactly 50 mm.
Changed to what gives nice prints (M92 E440) and only 37 mm is extruded. I must be overlooking somthing obvious here...]]> hsbontop Mendel90 Wed, 15 Apr 2015 13:58:54 -0400 https://reprap.org/forum/read.php?292,490857,497168#msg-497168 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497168#msg-497168
How does your extruder compare to a standard Dibond Mendel90 kit in terms of the gears?

I can imagine that if they differ from the standard 11:39 ratio, and you apply nophead's formula unmodified, there will be an extrusion discrepancy.

Regards,
Neil Darlow]]> neildarlow Mendel90 Wed, 15 Apr 2015 08:35:03 -0400 https://reprap.org/forum/read.php?292,490857,497105#msg-497105 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497105#msg-497105 hsbontop Mendel90 Wed, 15 Apr 2015 06:06:31 -0400 https://reprap.org/forum/read.php?292,490857,497094#msg-497094 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497094#msg-497094
Use nophead's 100mm of filament extrude method from the build manual to calibrate your E_STEPS_PER_MM value. It will get you to where you need to be in terms of extrusion.

Also, ensure your slicer has an accurate filament diameter configured. Small errors here can produce significant over or under extrusion.

I am guessing that you meant Retract Speed rather than Retract Acceleration. The difference between 40 mm/s and 50mm/s is small. I went as far as 80 mm/s which nophead is evaluating now to see if Marlin can actually achieve that speed.

For me it works but, like a lot of things 3D printing related, individual conditions may vary and produce different results.

Regards,
Neil Darlow]]> neildarlow Mendel90 Wed, 15 Apr 2015 05:34:09 -0400 https://reprap.org/forum/read.php?292,490857,497090#msg-497090 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,497090#msg-497090 Much better result but still ridges at the edges and the blobs remains despite changing retract acceleration to 50 and distance to 0.5. Skeinforge decided not to have the fan on during the print (this has now been fixed), could this be the reason?]]> hsbontop Mendel90 Wed, 15 Apr 2015 05:25:36 -0400 https://reprap.org/forum/read.php?292,490857,496318#msg-496318 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,496318#msg-496318
However the distance to get to that from 10 at 5000 mm/s^2 would be (66^2 - 10^2) / (2 * 5000) = 0.43mm. Since it also has to stop it would take twice that distance.

I did some experiments with different accelerations and jerks and they did not seem to make sense. For example jerk has no effect and some lower acceleration values were less smooth than higher ones. I suspect there are bugs in the planner code, so I need to have a look at what the pulse waveforms look like.]]> nophead Mendel90 Mon, 13 Apr 2015 10:46:46 -0400 https://reprap.org/forum/read.php?292,490857,496267#msg-496267 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,496267#msg-496267
Extrude and retract acceleration are both 5000 and extruder Jerk is 10.

I settled on 80mm/s recently in attempting to reduce the layer-end stippling effect with Brassfill. I increased retraction speed by 20mm/s increments until the effect was reduced to negligible levels.

I did not push the speed as high as 100mm/s but the visual improvement increased with each step up to 80mm/s. It may be that I have not fully achieved that speed and it would be good to know the achievable figure.

N.B.: Would have responded sooner but just returned from Norfolk to stable broadband.

Regards,
Neil Darlow]]> neildarlow Mendel90 Mon, 13 Apr 2015 08:59:17 -0400 https://reprap.org/forum/read.php?292,490857,495885#msg-495885 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,495885#msg-495885 I don't think Marlin can do 80mm/s on the extruder as it would be about 48kHz. What acceleration and jerk values do you use because I also don't think it will reach that speed in 0.5mm?

I do agree it looks like it would be better done faster. I am just not sure Marlin can go that fast. I am about the attach a logic analyser to see what speed it actually achieves.]]> nophead Mendel90 Sun, 12 Apr 2015 06:06:03 -0400 https://reprap.org/forum/read.php?292,490857,495734#msg-495734 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,495734#msg-495734
It does appear you have some over-extrusion.

The stippling on the corner is symptomatic of incorrect retraction. Not so much quantity but speed. I typically retract 0.5mm at a speed of 80mm/s.

The varying position of the stipples is caused by Skeinforge's Jitter setting which randomly positions layer endings within a set distance and defaults to 2mm.

Regards,
Neil Darlow]]> neildarlow Mendel90 Sat, 11 Apr 2015 16:06:00 -0400 https://reprap.org/forum/read.php?292,490857,495551#msg-495551 Re: Odd print problem https://reprap.org/forum/read.php?292,490857,495551#msg-495551 1. Over shooting, acceleration problem, lose belts?
2. Smal blobs in one corner, to much retract?
3. Uneaven top surface, overextrusion?

Amazing piece of engineering this, thanks nophead!]]> hsbontop Mendel90 Sat, 11 Apr 2015 08:11:58 -0400