Hello,
I found this free tool, from the company that makes SolidWorks, to be quite useful.
[
www.edrawingsviewer.com]
It can open and view a fair range of 2D and 3D files from various CAD programs, including many proprietary formats (especially .SLDPRT). Not only that, it can export them to STL.
You can use this program as a way of converting files from SolidWorks, AutoCAD, SolidEdge and Sketchup to STL data.
It's quite small and lightweight.
I think it's quite useful, so I thought I'd put a post about it here.