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gadgetfreak

Ultimaker Robot prints bad

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I thought it would be quite "easy" to print the Ultimaker robot from Cura, but I get bad results.

I get good results when printing a 20mm test cube or concentric circles.

But the overhangs in the Ultimaker Robot seems to give really bad prints for me :(

Can anyone give any feedback?

Also, it looks like when slicing in Cura 12.12A the result is better than in 13.03 - think I've used the same settings (0.2mm, 220 degrees) but I _might_ have had 210 in the other...

Check this album out:

IMG 1038IMG 1039IMG 1041IMG 1040IMG 1045IMG 1044IMG 1043IMG 1042IMG 1050IMG 1049IMG 1048IMG 1047IMG 1046IMG 1053IMG 1052IMG 1051

 

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If that's Ultimaker-White-PLA, you might need to increase the temperature a bit. (White PLA is not the easiest PLA to fabricate or to work with)

 

Thanks Daid.

It is Ultimaker-White-PLA (soon 2 years old) but it has been working fine for other prints, also printing fairly low temp.

I'm right now trying to print the hollow pyramid at 205 degrees to see how that turns out. I'll add it to the album soon.

But the UM robot looks quite bad with Orange PLA as well (check the album).

But how does the Ultimaker robot usually turn out at the overhangs (bottom of the robot belly for example) for you when you calibrate your printers?

If I recall correctly, you use a tweaked Kisslicer profile for printing those, but I assume you have printed it directly from Cura as well?

I'd like to print with a "known good profile/slicer" so perhaps if I could get the actual gcode for that UM robot you print, then I can test to see whether it is a mechanical/hardware problem or not :)

Is it a hard model to print?

Thanks in advance!

 

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I've printed the robot with the high quality profiles in Cura as well, which makes it come out just as good as with KISSlicer, only twice as heavy.

Another cause could be a problem with the fan-duct on the printer head, maybe it's not cooling enough near the object, or cooling the tip of the head.

 

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Is it a problem to print the UM robot with 0.2mm layer height?

I can't see that the fan duct would be cooling th printer head....

Now I just printed the hollow pyramid (should it be harder or not?) - updated pics in the same gallery as above - with this profile:

;TYPE:CUSTOM

M92 E833.000000

M109 S205.000000

;Sliced T:\Ultimaker Stockholm\Models\Hollow_Calibration_Pyramid\Hollow_Pyramid.stl at: Fri 22 Feb 2013 13:37:43

;Basic settings: Layer height: 0.1 Walls: 0.8 Fill: 20

;Print time: 0:44

;Filament used: 0.59m 4.99g

;Filament cost: Unknown

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

G92 X0 Y0 Z0 E0 ;reset software position to front/left/z=0.0

G1 Z15.0 F180

G92 E0 ;zero the extruded length

G1 F200 E10

G92 E0 ;zero the extruded length again

G1 F9000

;LAYER:0

;TYPE:SKIRT

Does it tell you anything from the pictures?

Daniel.

 

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Pyramid came out pretty good, didn't it?

BTW, in Cura, if you go into preferences, you can elect to save a profile on slice - it will save an .ini file with all the settings alongside the gcode - the head of the gcode only lists the basic settings (Cura does however include all the settings in a binary form at the end of the gcode, so that you can reload the settings from a previously-sliced gcode file - which is useful for going back and checking what you were doing right or wrong on a previous print).

 

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Looking at the orange robot in the gallery, it seems to be a problem of printing a bit too warm, and too fast, and not having enough cooling, especially on the parts that have overhangs. I would suggest to set the min layer time to 5 sec, maybe even longer.

 

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I think the pyramid came out pretty well.

That's why I think it might not be a mechanical issue.

But I'm surprised that the UM Robot would not print well with Cura defaults....how sensitive is it?

I mean if you guys (Joergen and illuminarti) would print it at 0.2mm layer height and 50mm/s and "default" Cura settings, would it come out good in a large temperature interval, or would you say the model is picky about the slicing parameters?

The benefit of using the UM Robot is that it's quite fast to print and is included per default in Cura, which most Ultimaker operators have (although I know that some of you might use Kisslicer or Netfabb as your default slicer).

 

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I have a printed fan duct "The Florian push fit variant" and it seems almost impossible it would cool the print head?

I'm printing an owl right now (http://www.thingiverse.com/thing:18218) - it will take about 18 hours because it's a solid print, and if it turns out well with all the details (I printed a really nice one a month ago in green translucent) I guess we could write off the fan as being the culprit, would you agree?

I'll take pictures of the owl tomorrow once it's finished after work.

 

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Thanks Joergen, I'll keep that in mind when slicing next time, it will save a lot of time to have 0% infill.

(actually, when i wrote solid I meant Cura default which I think is 20%).

But it does feel kind of nice with the "heavy" owl, and I guess it's more of challenge to the mechanics (to verify it's working ok) when printing long prints.

 

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One thing that you might like to check up on is the initial print bed height. I've noticed that things go badly if you don't have the height precisely right when you start printing. Things get even worse when your print bed is warped (as I'm starting to suspect mine might be). If the print head is too close to the layer it is printing on top of you get a "squidging" effect which causes some layers to flatten out and causes ridges on vertical surfaces. I'm presently playing with this at the moment to try and get the sides of my boxes as smooth as I can. On my machine, if I adjust the height at the corners (as with the lovely bed levelling wizard in Cura) I find that in the middle of the print bed the head actually crashes into the baseplate and the output, so I have to tweak things a bit.

Of course it is a compromise, if you make the platform too low it means that the first layer doesn't stick and then you just end up with a ball of wool being produced. If you make it too high you get the head digging into the output and producing "squished" output.

 

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RobMiles, thanks for your input. I have calibrated the bed as good as I possibly can and with a model with this little width, it's actually quite forgiving.

I did have a warped bed over a year ago, but the bed and initial height I'm pretty sure I nailed down good now.

Daid and others: I have now updated the album with pictures of the owl I printed over night. It's not perfect, but it's pretty good and a lot better than the UM Robot. You can also see the fan.

IMG 1046

IMG 1047

IMG 1048

IMG 1049

IMG 1050

 

I'll try to print the UM Robot in high quality (0.1mm layer height, 220 degrees) next.

 

Thanks for keeping up the troubleshooting :)

 

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The new "High quality" UM Robot still has overhang issues :(

I added two pictures of that in the album:

IMG 1053

IMG 1052

as well and result from Jelle Boomstras bed leveling gcode "BedLevelv4"

IMG 1051

From the bedlevel it look like I have a little backlash in X judging from the two rightmost circles which does not touch?

The setting for the UM robot for this print was as follows.

What's next, take the pain and replace all belts?

[profile]

filament_diameter = 2.89

nozzle_size = 0.4

wall_thickness = 0.8

retraction_enable = False

max_z_speed = 3.0

travel_speed = 150

print_temperature = 220

print_speed = 50

retraction_speed = 40.0

layer_height = 0.1

solid_layer_thickness = 0.6

fill_density = 30

support = None

enable_raft = False

filament_density = 1.00

skirt_line_count = 1

skirt_gap = 6.0

retraction_min_travel = 5.0

retraction_amount = 4.5

retraction_extra = 0.0

bottom_layer_speed = 15

cool_min_layer_time = 10

fan_enabled = True

bottom_thickness = 0.2

object_sink = 0.0

enable_skin = False

plugin_config =

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 = 5

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 = 50

support_distance = 0.5

infill_type = Line

solid_top = True

fill_overlap = 15

bridge_speed = 100

sequence = Loops > Perimeter > Infill

force_first_layer_sequence = True

joris = False

retract_on_jumps_only = True

hop_on_move = False

 

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Out of interest I printed a robot (at Cura default settings) and got almost exactly the same results as you. There is some sagging across the back and lack of resolution of the features. I used white PLA from Faberdashery. I'm not massively unhappy with the results really though, I'm wondering if white is just a tricky colour. It might be interesting to try different plastics or perhaps drop the temperature to reduce the sagging.

I find it ironic that Ultimaker picked such a hard to print object as their mascot and then shipped the demo one configured to print out in such a small size. If they made it a bit larger I'm sure it would look much better.

My favourite showpiece is the Pentapod rocket on Thingiverse:

http://www.thingiverse.com/thing:26424

This prints fairly quickly and has no overhang problems.

BTW I think the owl looks ace.

Rob

 

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I have found that overhangs print much better at extra slow speed. 20mm/sec is the slowest I've gone and they look better at that speed than at 50 or 70mm/sec. It might have to do with not enough fan - not sure, but I can see the problem as the filament is being laid down - the filament pulls/shrinks as it is being laid down and doesn't go where it is supposed to but if you slow it down it goes to the right spot - I know some of you are thinking it's a belt issue, but for non-overhangs I can print no problem 5X faster.

Anyway I'd be tempted to dial down the ultictonroller to 40% when you get to the overhangs.

 

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Thanks a lot guys.

I did try printing with 25mm/s.

A tiny bit better, but not that much better on overhangs.

I tried rotating the robot with the face towards the fan but then the whole robot came out a lot worse, really strange.

I also tried with Faberdashery pink PLA, no real difference.

(no new pictures, I didn't get the time to take new ones)

I have an unassembled UM kit (my colleaugues) sitting next to me that we will start assembling tomorrow - hopefully it will be done by the end of the week - it will be really interesting to compare to this one.

I'd really like to try this with some gcode that somebody else has gotten good results with (I have V3 bolt/new extruder /V2 head, albeit mounted onto a really old Ultimaker (from June 2011 so it's rev.1).

 

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I have an Ultimaker with extruder upgrade, the old V1 hot end and self-made double-cooling. For slicing I use Cura, PLA is from Faberdashery. And this is how the Ultimaker Robot looks like on my machine:

urobot_s.jpg

click for a larger image

As you can see, I am still having some minor issues with overhangs.

The slicing profile is a slightly tweaked standard Cura High Quality setting: Ultimaker Robot GCode

 

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That looks so much better than mine!

Double cooling looks really good. Is it on thingiverse?

Thanks for the gcode, I'll try it tomorrow!

btw, if you have the new extruder (and v3 bolt) you might want to change your e-steps value to 833 for even better prints? I saw you had 865 in the gcode.

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