Is there a way to convert a Solid Works file into a Sketch Up file without the use of a conversion software?
Well, you can export a SolidWorks model to VRML, STL and 3DXML-which Sketchup may be able to import. The problematic issue is getting results that are usable. Most of these are triangulated mesh formats and don't include materials or textures.
Here is a list of file types that can be imported: What kinds of files can I import into SketchUp? | SketchUp Knowledge Base
It looks like options are very limited. If you have SketchUp Pro then I guess a dxf might be best. Otherwise you might need to save a 2D image and import it; I don't know if SketchUp has a trace function.
Do STEP files convert into Sketch Up?
No, it looks like Sketchup is a mesh-based modeller. Step files are based on NURBS-which have to be converted to a mesh, so you're back to where you started.
You might try exporting the model to VRML97, opening it in Blender and then exporting it to 3DS.
You'll lose any materials you've assigned, but it won't cost you anything, monetarily speaking.
I have been using method from this tutorial: http://www.javelin-tech.com/blog/2011/03/export-sw-to-sketchup/ .
It works pretty well for me.
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