"Step" files from Moi are good for direct importation!
(but the trick of the Sphere "unlocked" always indispensable for modify it inside DSM - 2 seconds! ;)

- Direct export save as STL, OBJ, SKP works fine!

- Only nurbs format Sab / Sat should have the trick of the "command line" shown above! (5 seconds) :)

PDF 3D...seems always not visible but maybe i forgotten something again! :)
(and i am not sure to have always a pdf 3D viewer! If you have a Pdf 3D on line...
(or use the V 1.0 collector : http://designspark5.rssing.com/chan-33180489/all_p3.html