Importing .STEP Files (and STL)


I designed this from scratch:

and managed to get this:

The manufacturer of the device then was able to send me .STEP files with which I was no able to do much. He now sent me .STL files. These I can import. What I get is this:

Beside the files being extremly large, I cannot use them really (the scope is to write a manual and videos).

I do not see a way of being able to use the converted result. It is just a bunch of lines without any grouping.

Anybody has a sugestion?

PS: of course I can use the one I designed from scratch. But there are many more to do. Do much to do them manually.

The STL format is a surface skin that is comprised exclusively of triangles, that’s how the data is saved. There are tools and methods to clean them up, to merge complainer faces back into single surfaces and simplify geometry, but not extract the parts of the assembly back into groups and components.

Depending on how they are made STEP file may retain the grouping of individual parts of the assembly. I work with STEP files often and there are several ways to get them into SketchUp ( the best ways are not free). Post one of the STEP files here (or a Dropbox link if it’s too big) and I’ll import it into SketchUp and send it back to you to see if that workflow is going to get you what you need.

Have you tried Transmutr I’m pretty sure it supports.stl files.
It’s a paid for extension but has a free trial

Tried it but I still have lots of triangles.

The best results really are:

  • export from C4D (Cinema 4D) to .STEP
  • import into FreeCAD
  • export to .DAE
  • import in Sketchup

Then I have curved surfaces.

Strangly when exporting from C4D directly to DAE and then into Sketchup gets you lots of triangles

Hi @endlessfix

here is the file. Would be intrested to know what you used to convert. I am OK to pay money if it saves me work. (2.1 MB)

PS: this file makes FreeCAD crash when I import it. You can shortly see the imported result and then it crashes.

Looks like the previous .stl you were sent by the manufacturer was just an outer shell. The assembly grouping information is present in the .STEP file, so if it’s converted correctly from that file to .stl as @box has done it will have separated geometry even as .stl. Cool, that looks like a totally viable completely free route to go.

I import .STEP directly into SketchUp using the Simlab STEP converter extension as I have to do it often and I appreciate that the results are very clean and it has some polygon control built in (the importer has a coarse-fine slider control that helps me dial in the right balance of tessellation vs file size for each application) However, even on the coarse setting the files can be quite big and heavy to deal with.

I generally clean up the imports using CleanUp3 to merge coplanar faces which is a crucial IMHO step for yielding workable files in SketchUp in this process (for .STEP or .stl). Running CleanUp on this file for instance removed 41k edges and 39k faces, other than that I have not touched the files, the grouping and color info is as imported. I’ll post the original and the cleaned version.
ShellyPlus Import.skp (4.8 MB)
ShellyPlus Import CleanUp3.skp (3.5 MB)

1 Like

Crazy. I tried 4 of them that Google proposed. Only got tousands of triangles. Converted 11 MB STEP to 72 MB STL.

What converter did you use?

Generally - Sketchup sucks at importing. It just does. It’s a shame and it’s a long-standing shame. Because - as @TheOnlyAaron often says in his many, many videos: Sketchup is a tool that should be used along side other tools. So getting data in and out is crucial. Having to go through all of these things that are being suggested here is just painful.

Every 2 month or so I am trying to find an easy way to convert our construction files from SolidWorks to Sketchup without loosing too much time and effort. Tried everything - SimLabs Step-Converter is nice but does something really weird to the geometry so you cannot really modify the imported data in Sketchup afterwards (I’ve been in contact with them about this a couple of times but they don’t really care and told me to find another tool…) :slight_smile:

So the best options at the moment really are:

  • STL
  • DWG
  • 3DS


  • CleanUp3 (You need to make sure to check “merge coplanar faces” to get rid of your triangles"
  • MaterialTools - Remove Materials

If you have money to burn we work with Skimp to simplify complex imports - got good results from that.

Still - all in all it’s still a pain. And if you are using a Web-Version of Sketchup - well: good luck to you! :crazy_face:

Thank you for your honest assessment.

I am trying to get hold of usable graphics to create a website where we will sell home automation equipment. It will go with comprehensive graphics and instructions (which most of these tools are not good at).

I am lucky to have a manufacturer that shares the graphics and now I am sort of stuck in making them usable.

I guess I was being to naive to think graphic formats would be easely interchangeable. Coming from HPGL as my first “graphic format” back in 1988 where PenUp and PenDown would be enough to draw an object I now realize that it is not that easy anymore :wink:

I am still exercising with CleanUp³. Trying different options.

Just trying to do as you explained. Sorry not to see the post anymore…