print in cura looks different than in sketchup

[impeham 0]

i've made a simple component in sketchup - a box with an internal erased area - see image.

when i export it to STL and open in CURA, for some reason, it shows both a top and a bottom (see image) which doesn't exist in the original sketch. what is the reason for that??

[kmanstudios 1,120]

If you are using sketchup, it is not manifold or not. There are people here that have experience with this, but even if not made in sketchup, it being non-manifold is the issue.

[gr5 2,167]

See how the inside walls are gray?  That's the problem.  Right click on those and do "reverse faces".

 

More info here: https://i.materialise.com/blog/3d-printing-with-sketchup/

[darkdvd 975]

No, the walls are fine : he made a hole on the top face : the color is grey because we see the Inside of the object.

Edited April 2, 2018 by darkdvd

[geert_2 557]

The only real solution is to not use SketchUp for 3D-printing. It is going to keep causing you endless trouble with every model, and it is going to slow you down a lot, and cause endless frustration.

 

Try DesignSpark Mechanical instead. This is freeware, it only requires registering. In two years time, and many hundreds of models, I never had any issues with its STL-files. Never.

 

DSM is very easy to learn: it has a similar push-pull interface like SketchUp, and there are lots of good tutorials en demo-videos on Youtube and elsewhere.

 

[kmanstudios 1,120]

1 hour ago, geert_2 said:

Try DesignSpark Mechanical instead.

I am going to second this as I have heard great things from others about this software as well.

[impeham 0]

It does seem a sketchup issue. i tried creating the box in another method, and it looks fine for printing with it. i'm still learning this tool as it looks very powerful and easy. i'll wait to see how it is with the printing.

 

Thanks for the help.

 

[gr5 2,167]

@impeham arrrg.  Did you even read my post?  Sorry - sometimes I know exactly what the problem is - I explain the answer very simply - and feel I'm ignored.  If you want your box to be filled in when cura runs - do exactly what you did.  Make the inner walls gray.  Exactly like your picture.  To fix it, right click on ALL visible gray walls and select reverse sides.  I'm talking about doing this in sketchup, not cura.

 

Also, although I recommend learning DSM eventually, if you are a pro in sketchup, then the guide I linked to above will be very helpful.

[kmanstudios 1,120]

8 hours ago, impeham said:

i'm still learning this tool as it looks very powerful and easy.

Is this Sketch-up or did you change software when you said 'Different method?"

[SandervG 1,521]

19 hours ago, geert_2 said:

Try DesignSpark Mechanical instead

Looks like it is only available for Windows, isn't it?

[geert_2 557]

2 hours ago, SandervG said:

Looks like it is only available for Windows, isn't it?

Yes, I think so. DSM is derived from the commercial SpaceClaim: it has the same user-interface, only it has less features. (So you could use the SpaceClaim manuals too, as long as you calculate in that DSM does not have all SpaceClaim features.)

 

But DesignSpark Mechanical can run in a VirtualBox VM, although slower and at lower rendering resolution. So, for those with a Mac or Linux, they could try to install it in VirtualBox, if they really want it. Find an old genuine Windows installer-DVD from a scrapped computer (so you stay legal), and try that. You need to google a bit on how to enable 3D graphics in VirtualBox.

 

I don't think I can insert PDF-files here in the forum? Otherwise I could add the manual I wrote for my own reference, on how to install DSM in VirtualBox. I could copy the plain text as well if you want, but it is quite long. Or maybe I should make a new thread for that?

 

[SandervG 1,521]

42 minutes ago, geert_2 said:

I don't think I can insert PDF-files here in the forum?

 

Now you can

[geert_2 557]

For those who want to install DesignSpark Mechanical in a VirtualBox virtual machine, I made a new topic:

https://community.ultimaker.com/topic/22327-manual-how-to-install-designspark-mechanical-in-virtualbox/

 

You could try this if you do not have a Windows computer, or just for testing purposes, without influencing your current system too much.

 

[gr5 2,167]

That didn't work for me.  I have ubuntu.  I keep a windows machine around and its primary purpose is DSM.

[impeham 0]

13 hours ago, gr5 said:

@impeham arrrg.  Did you even read my post?  Sorry - sometimes I know exactly what the problem is - I explain the answer very simply - and feel I'm ignored.  If you want your box to be filled in when cura runs - do exactly what you did.  Make the inner walls gray.  Exactly like your picture.  To fix it, right click on ALL visible gray walls and select reverse sides.  I'm talking about doing this in sketchup, not cura.

 

Also, although I recommend learning DSM eventually, if you are a pro in sketchup, then the guide I linked to above will be very helpful.

Hi yes i have read it - thx for the reply. i eventually started the model from the beginning in another way - not by deleting a box inside a box and it seems fine now.

 

what are the benefits of DesignSpark Mechanical over sketchup? why is it better than sketchup?

 

[gr5 2,167]

Sketchup allows you to draw an infinitely thin wall.  It's great for architecture where people don't care if a wall is infinitely thin or not.  And you can map visual textures onto planes and make nice renderings really fast.

 

Normal CAD for "real" things - to build real things - only creates solids.  It's very hard in DSM to create something that isn't solid.  Everything has a continuous surface that clearly defines what is inside and outside the part.  

 

For example, if you designed a cube in sketchup and forgot to put a bottom to it, you might not notice in sketchup but that cube only has 5 sides - no bottom.  It's infinitely thin.  In most CAD you can't do that - you might start with a rectangle in just two dimensions (so it does let you do it briefly) and then you immediately extrude that rectangle into a 3rd dimension and now you have a nice solid part.  If you click on a side and try to delete it - you can't.  Because that would make it not-a-solid.  

 

The interface in DSM just makes it hard to create impossible things that can't be built in real life.

 

If you follow that link I posted about sketchup - it's really well written - simple to read - with nice pictures explaining everything.  And it has links to great sketchup tools to test that your model is manifold.  If you have been using sketchup for a year or so you probably don't want the pain of learning a new CAD and you might consider sticking with sketchup but learning a few extra tools and techniques.

 

Here is a very simple guide to find the best possible cad software.  I didn't create this but I think it's the best guide out there:

https://www.gliffy.com/go/publish/5271448

 

[impeham 0]

thanks for the detailed explanation - sounds very logical. I'll definitely check an alternative - leaning toward SolidWorks.

[kmanstudios 1,120]

36 minutes ago, impeham said:

thanks for the detailed explanation - sounds very logical. I'll definitely check an alternative - leaning toward SolidWorks.

I know solidworks has a good rep for 3D printing

 

Only downside is the cost.

[geert_2 557]

17 hours ago, impeham said:

...

what are the benefits of DesignSpark Mechanical over sketchup? why is it better than sketchup?

 

 

Reasons for prefering DesignSpark Mechanical over SketchUp:

 

1) I never had any STL-file problems with DSM, thus never had printing problems. With SketchUp you are going to have them every time, and you are going to waste days and weeks, and get very frustrated if you have deadlines and work to do.

2) In DSM it is easy to round corners, or add chamfers, which is often needed in technical parts.

3) It is easy to undo things: to delete or change existing roundings on a design, move holes, change extrusions, etc... This is a major benefit when you often have to change existing designs. (Compare this to for example FreeCAD, another freeware 3D-editor: in FreeCAD you can create very complex designs, but most of the time it is impossible to change them afterwards, without breaking everything else.)

4) As gr5 said, in DSM we never have problems with "empty" cardboard models. It are true solids. Contrary to in SketchUp: very often the walls do not touch each other, but there are invisibly small openings, like a paper model house that is not glued together perfectly. It may look okay from a distance, but it is not water-tight. These are not solids, but "empty cardboard models" that can not be printed, and that are horrible to correct.

5) DesignSpark Mechanical is much easier to learn than for example Solidworks (although Solidworks is way way more powerfull). Especially if you come from SketchUp.

6) It is free, contrary to Solidworks and similar very expensive packages.

 

Disadvantage is that you can not make colorfull renderings, so you can not add brick textures, wood, grass, etc... But these can not be printed on an FDM printer anyway, so no problem for me. If you need colorfull renderings and organic shapes, you might need Blender (free), or Maya, or something similar. For technical renderings, you might need Solidworks or similar. Or Form-Z.

 

Also, DSM is somewhat limited in features, compared to its commercial sister SpaceClaim, or to Solidsworks. But for 3D-printing, it is more than sufficient.

 

The best thing you could do is watch a few demo-videos on Youtube (also of other candidate programs, FreeCAD, Onshape, Blender, Solidworks, Maya, Form-Z...), and see wether it appeals to you. Not every user-interface appeals to everyone (for example, I can't find my way around in Onshape, while others can do wonderfull things with it). In the end, even if you spend a day watching demo videos, it will save you weeks of time. If you have a company and need to exchange designs with manufacturers, you might prefer a commercial package. As a hobbyist, or educator, you might prefer freeware like DesignSpark Mechanical.

 

At least, this is my viewpoint, but of course you have the right to see things differently. 

 

[eldrick 65]

Don't overlook Moment of Inspiration: moi3d.com  It is excellent.

 

 

[kmanstudios 1,120]

In the interest of full disclosure, the full version is a paid for version:

http://moi3d.com/purchase.htm

 

Not a bad price though......

[gr5 2,167]

Before you "choose" solidworks - look at the price, lol.  If it was only $1000 I'd consider it.  Maybe.  If work pays for it then go for it.  It's fantastic but takes years to get a good competency.  It took me a year before I could use DSM without thinking (my fingers move without me thinking - I click a face, hit XKV, edit on that face, hit D, hit SPACE, click something, hit P for pull, etc.  

 

Same was true in sketchup.  Hit O for orbit, then Z, then S (was it S?) for select, click on something, move it, pull it, etc.

 

[geert_2 557]

19 hours ago, eldrick said:

Don't overlook Moment of Inspiration: moi3d.com  It is excellent.

 

 

Yes, I have the no-save demo-version of moi. It is good if you know exactly what you want to make, thus if you have a clear picture in mind. And it can handle organic shapes too. But it is difficult to rework existing parts. So it is less suited for technical things that need frequent adjusting. It is more geared towards artwork. The good thing is that you can install a one-month free demo-version to try if it appeals to you, or you can install a timeless no-save version. It requires very little system resources, so runs on less powerfull hardware too. Also, it has a good forum and good support from the author.