I create a simple box 2" x 1 1/4" x 1/8", then I used the Export STL extension to export this to an STL file. Then I viewed this file in a generic STL viewer and the units were all wrong. I then tried to import it back into sketchup and it imported in as roughly 2mm x 1.5mm x 0.5 mm. What could I be doing wrong?
See this thread.