I’d recommend using SketchUp Make 2017. It’s the desktop version. I like to use Blender, a free program, to convert SketchUp models into various filetypes. I just export a .dae from SketchUp, then I can import it into Blender. From there, you can export the file as a .abc, .3ds, .fbx, .ply, .obj, .x3d, or .stl.
If you like making 2D plans, then SketchUp Pro has LayOut which is pretty cool. SketchUp is compatible with Mac & Windows, but I’m not sure how many computers a pro license allows you to make copies on. It’s probably worth finding out.
Also, SketchUp Make isn’t for professional work, but SketchUp Pro is.
I’m using Make 2017 now, but have been having issues with the STL export extension - thus my interest in an upgrade. I had not considered Blender as a go-between.
Does anyone have an answer to the number of computers upon which Pro can be installed for those of us that have more than one?
It can be installed on 2 units.
I am a hobbyist using 2019 Pro. There are some feature differences that drove me in this direction. A good Nvida graphics card make life much easier.
There’s another avenue to .stl files that doesn’t rely on an extension: Upload your model to the 3D Warehouse! Once you do so, wait a bit while Trimble translates your file into various versions (they generally create 2017, 2018, and 2019) AND after they added .stl for SketchUp for Schools users, they also make an .stl file!
To download, you have to go to your 3D Warehouse model in a browser (NOT in SketchUp’s internal 3D Warehouse window). Once on the ACTUAL model page (not when shown as one among a number of models), there’s an option to download the .stl version.