HELP: cura keeps leaving holes in my models.

[FishicallyDumb 0]

So im trying to edit some .stl files to use in cura. Im using Sketchup to edit the file, export as .dae, and convert to stl thru Accutrans3d. 

 

 

This is the unedited file on the right and the edited file on the left. Everything looks good. But as soon as i go to preview to view the layers:

 

Why is this happening and how do i fix it.

 

Also sketchup:

 

Thanks.

Edited February 4, 2020 by FishicallyDumb

[nallath 1,120]

Sketchup is infamous for it's ability to create meshes that look good, but are a complete mess in reality.

I suspect that's the case here as well. If you look at the model in x-ray view (preview; selector in the top menu bar called "view type"), and you see red areas, the model is broken. There are a number of online tools that do their best to fix it, but they might not always succeed.

[geert_2 557]

The screendumps below show why you should not use SketchUp. The vectors do not match up, they do not connect. So you do not get watertight solid models. SketchUp models are a mix of separate surfaces and half-solid parts. Especially if you then do boolean operations on these, it becomes a mess.

 

Below this effect is shown in simple text, before it is extruded into 3D, but the same also happens in other SketchUp models.

 

SketchUp was designed for visual representations only: of buildings, like in games, or for Google's original Earth and Maps views. Not for 3D-printing.

 

If you want to use it for 3D-printing, you manually have to zoom in extremely, and manuall move and close the vectors (see the red arrows where the gaps are that need to be closed).

 

 

Characters with openings (non-matching vectors) don't fill, don't extrude correctly into 3D, and give problems when printing. Idem for other models.

 

A better solution is to use a program that is designed for modeling solids, for 3D-printing. I use DesignSpark Mechanical. Other people use Onshape, or Fusion360, or (student versions) of Solidworks, and lots of other packages.

 

Search on Youtube for demo videos of 3D-editing programs, and then try one that appeals to you.

 

[thorsenrune 11]

@geert_2, I gave up on sketchup, too many times my models were not manifold and thus not slicable. Often due to numeric errors. Secondly its not parametric so its impossible to size preciely.

Anybody using Onshape?

 

 

Edited March 4, 2020 by thorsenrune

[eldrick 65]

The only virtue of Sketchup for 3D printing is that it is free. Unfortunately it is worth the price.

[geert_2 557]

50 minutes ago, thorsenrune said:

@geert_2, I gave up on sketchup, too many times my models were not manifold and thus not slicable. Often due to numeric errors. Secondly its not parametric so its impossible to size preciely.

Anybody using Onshape?

 

 

I have tried Onshape, in the beginning when you could still have 10 private models (all above 10 would become public, accessible to the whole world). But I don't think you can still have 10 private models? Maybe 4? Unless you pay big money per month.

 

Anyway, I could not find my way around in its user-interface: I can't find anything and can't get anything done. Its phylosophy seems to be incompatible with mine, so I stopped using it. This could be my problem of course, since some other people *can* make great designs in Onshape.  :-)  I have a very different graphics background than most other people.

 

Now I use DesignSpark Mechanical, freeware from RS-components (only requires registration), and a feature limited version of the commercial SpaceClaim. Its phylosophy is close to that of SketchUp, so the transition is easy. And there are lots of good video-tutorials on Youtube. You can make exact dimensions, but you can not set variables and stuff like in Solidworks.

 

Others here use Fusion360, but I haven't tried that yet.

 

I would suggest that you watch a couple of demos on Youtube of all candidate-programs, and see how they appeal to you. Everyone has his own taste and requirements.

 

[thorsenrune 11]

@geert_2, great post.

 I have been using Onshape for some time as I am keen on the parametric idea (engineering mind). I totally follow you on the interface and I have some discussions on the forum, I'd like to quote you if thats ok, since 'phylosophy seems to be incompatible' is shared by my students. I work on the idea of co-designing so I'd like to find a CAD that 'anyone could use' & parametric for easy scaling & webbased (no installation and work anywhere). So far Onshape is the closest and working open-source the public drawing is not a problem (by the way- there are so many now that nobody will ever find your pre-patent drawings anyway - just give it some sick name). However it is big money if they change policy  (as for DesignSpark & SpaceClaim) so I'm always on the lookout for opensource.

Also my enthusiasm about SAAS is scarred by beeing too much at the mercy of the forced-upgrade-to-a-buggy-version-but-we-will-never-admit-it (been there with google, onshape and others)

Have you checked jsketcher? Could be a really nice one if it was alive https://github.com/xibyte/jsketcher/issues/95.

As for the virtue of Sketchup was that even a child could use it. You can't say that about Onshape, Solidworks, Autoxxx and friends.

 

P.S. do you ad @ as in @eldrick to notify people in this forum?

Edited March 4, 2020 by thorsenrune

[geert_2 557]

@thorsenrune: I don't know what this "@-thing" does, other than drawing visual attention, so I rarely use it. :-)

 

And yes, you can quote me on the Onshape phylosophy. I am used to very wel organised graphic design packages, with easy navigating through logical menus and toolbars. Functions should be where you expect them to be. But in Onshape all functions seem to be randomly splattered all over the screen, and often hidden, without any logic (or at least I can't find it). I had to consult the manual *every time*, again and again, even for the simplest functions like saving or exporting a file. Further, I couldn't orient and rotate the models on-screen: they would tumble upside-down and then I couldn't get them upright again. While in other software rotating works so smoothly and intuitive. Also, often I couldn't select the parts of a design that I wanted, and I kept losing the selection, or it selected other stuff than I wanted. And so on and on, endlessly... Thus, even though Onshape theoretically had a lot of possibilities, I couldn't find and use them. And it was too unpleasant. By the way, I had similar problems with older SolidWorks versions, which came from the same engineers I think, although to a lesser degree (I don't know the newer versions). I think this is a pitty, and the Onshape-engineers should really reconsider their user-interface. It should be very intuitive, and very straightforward and logical. It should adhere to the UI-standards and logical menus that were set from the very beginning in graphic design computers, in the 1980's, even before Windows, Mac and Linux came along. Then it could have great potential. It is like adhering to the standard way pedals and the steering wheel in a car do work.

 

What I like in SketchUp is the simplicity of its user-interface, with its push-pull concept. It is very straight-forward and logical. For me, DesignSpark Mechanical is close enough to this, but it is better for engineering parts, based on geometric shapes, and it never caused any printing problems.

 

If you would prefer a more architectural- and interior-oriented CAD-software, that can do both push-pull and numeric design, have a look at "Form Z" from AutoDesSys. They now have a freeware but feature-limited version too. The user-interface is close to that of SketchUp. A unique feature of Form Z is that it can do very smooth nurbs (=3D-splines and organic curves).

 

For a demo, see:

 

I have played around with their beta-versions in 2014-2015. But this is offline-software (or at least it was back then; I don't know how it evolved since). Also, I don't know how solid and error-free their 3D-models are, for 3D-printing. But its free, so you can try. :-)

 

For teaching, indeed ,I can see the value of online-software, compared to having to install it on all classroom- and student computers. Here at our university all teaching-software is installed and maintained on one master-computer only. And then this master is mirrored automatically to each student-pc in all classrooms. This combines the advantages of both online- and offline software. Maybe that concept might also be an option for your classes? On our laptops and in our offices, we can install what we want, as long as it is legal and virusfree, of course.