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Stringing or something else?


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Posted · Stringing or something else?

Hello, I'm a bit of a newcomer to ultimaker, I've done some printing a few years ago and I'm working again now with an UMS5, and I'm trying to print our some models I've created. 

 

I've attached photos of my print, and the initial model. I'm not even sure what parameters to mess with, does this look like stringing?

Screenshot 2021-10-19 165553.png

photo_2021-10-19_16-53-25.jpg

photo_2021-10-19_16-53-24.jpg

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    Posted · Stringing or something else?

    I can think of about 8 reasons this might be happening.  I don't want to explain all 8.  Please post your project file (in cura do "file" "save project") and post that file here for us to look at.

     

    It could be the model.  It could be your settings.

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    Posted · Stringing or something else?

    "It could be the model.  It could be your settings."

    @gr5 - I'm going to go out on a limb and wager my 2 cents on the model being the problem.  Zooming in on the second image it sure looks like bad surfaces on the "gear teeth".

    @bryce_jensen The Project File will tell.  

     

    Untitled.thumb.png.ea5e26cb0a32613cc6dc7338cf4dbe68.png

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    Posted · Stringing or something else?

    Your model defects look way too nice and too regular for "stringing".

     

    So I guess it is a defect in the model. This happens all the time with models made in SketchUp, and it also seems to occur with Blender models and some other editors that were originally developed for visual 3D-modeling (like games, simulators, animations, 3D-art). These editors often produce a sort of "cardboard" 3D-models with seams along the edges, and with duplicate surfaces, etc. Models for 3D-printing however do require solid, water-tight models, without any seams, without duplicate surfaces, without internal surfaces, etc. The models should be like a solid block of iron, instead of glued together cardboard.

     

    Real stringing looks like very irregular strings or hairs, when the nozzle is leaking while traveling through the air between different areas. Thick strings usually come from material leaking out of the nozzle (=from the inside), and thin hairs usually come from material accumulated on the outside that is sagging and touching other parts, and then pulling a hair. "Insect antennas" come when a leaking drop is deposited onto the next item the nozzle encounters, after traveling through the air. On the following pass, the drop is deposited onto the previous drop, and so on, causing an upwards growing insect antenna.

     

    This pic shows stringing between both pilars, and sagging (like spaghetti) on each pilar, while printing free-hanging supports for a bridge that has to come between the two pilars.

    DSCN5679b.jpg.369ab32c7990bf99558d198e2ecf8321.jpg

     

    This pic shows a little bit of stringing on the top cones, and sagging below the long unsupported overhangs.

    image.thumb.png.7275d9cf19f9e8da73bd600958b55bd9.png

     

    This are "insect antennas" and strings and hairs.

    microscope5.thumb.png.0a792ceff97c232fc3c2e9ac90f6de48.png

     

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    Posted · Stringing or something else?

    Okay - I agree that it's most likely the model.  I think it is probably the model normals.  Here are some suggestions for 2 different CAD systems:

     

    repairing models
    If this model is from blender google about the "remesh modifier".  And also about "normals" in blender.
    More here: https://www.sculpteo.com/en/tutorial/prepare-your-model-3d-printing-blender/

     

    If this model is from sketchup read this:
    https://i.materialise.com/blog/3d-printing-with-sketchup/

     

    There are also lots of repair services including a plugin for cura.  But fixing normals is usually very very easy.  Particularly in sketchup.  Most CAD don't create bad normals.  Normals tell Cura which side of every triangle in the model is "inside" and "outside".

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    Posted · Stringing or something else?

    Thank you all for the replies. 

     

    To be clear, I'm using Fusion 360 for generating the models. Does it typically have errors like sketch-up? 

     

    I've attached the .3mf file of the print settings. I also took a screenshot of the sliced preview showing the erroneous features aren't present.

    Screenshot 2021-10-20 151811.png

    UMS5_Body2.3mf

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    Posted · Stringing or something else?

    No, Fusion is really good about exporting clean models.  There can be user errors in creating the CAD model (unions of pieces that aren't quite attached is the main one) but all-in-all the AutoDesk programs work well.

     

    If your version of Fusion has NetFabb included I think you can use it for STL repair.  AutoDesk used to have a free site using NetFabb but it's gone.  I've been using another site and it gives reports on the model repairs.  The first here is for the Body2 part (which Cura declared to be non-watertight).

     

    --> 0 Naked edges (?)
    --> 0 Planar holes (?)
    --> 0 Non-planar holes (?)
    --> 2 Non-manifold edges (?)
    --> 4 Inverted faces (?)
    --> 8 Degenerate faces (?)
    --> 0 Duplicate faces (?)
    --> 0 Disjoint shells (?)
    -> Repairing: 100.00%
    ----- Repair completed in 415ms ------
    -> Vertex count changed from 467 to 477 (+10)
    -> Triangle count changed from 950 to 962 (+12)

     

    This one is for the Track Pad model (Cura declared it to be watertight) that had the problem.

    -> Reading file and indexing vertices
    -> Analysed your file:
    --> 0 Naked edges (?)
    --> 0 Planar holes (?)
    --> 0 Non-planar holes (?)
    --> 0 Non-manifold edges (?)
    --> 0 Inverted faces (?)
    --> 0 Degenerate faces (?)
    --> 0 Duplicate faces (?)
    --> 0 Disjoint shells (?)
    -> Repairing: 100.00%
    ----- Repair completed in 1200ms ------
    -> Vertex count changed from 1102 to 1708 (+606)
    -> Triangle count changed from 2212 to 3424 (+1212)

     

    The vertex and triangle counts went way up (and it took 3 times as long to repair) but I have no idea what that really means.

    So it appears that there really wasn't much wrong with the models you uploaded and they sliced fine for me.  That print you did sure looks like a bad model though.  Below is a screenshot of my slice read into AutoCad (I turned off the travel moves to unclutter).  It also looks fine.

    body2.thumb.png.4337a10927d626e47c2e6778e5dc2f8a.png

     

    If you will post the gcode file that you printed I can look at it.  Since you used ArcWelder it can't be read back into Cura (yet).

    @ahoeben did much work on ArcWelder and maybe he has a take on this.

    That definitely isn't stringing we see in those photos.  They look a lot like triangles (when viewed in the plan) right down to the short legs that are within the gear teeth.  I was surprised there wasn't more wrong with the models.

     

     

     

     

     

     

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    Posted · Stringing or something else?

    I don't think this is the right project file?  I opened it and it slices fine but there are no blue lines (travel moves) where you had those stringing-like lines.

     

    Evidently I need the exact project file that went with that exact photo where it had the problem.  Maybe.  Because that project file you sent just doesn't seem to match up with that part as far as I can tell.

     

    Maybe try printing it again but halt the print as soon as you see it doing what it did before?

     

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