Hi, Your post is still flagged "This post has NOT been accepted by the mailing list yet" so nobody gets it on the mailing list. You need to complete registration. <http://forum.openscad.org/mailing_list/MailingListOptions.jtp?forum=1> Re your issue. When I do: import("5mm_Calibration_Steps_fixed.stl"); translate([40,0,0]) import("5mm_Calibration_Steps_fixed.stl"); I get: Compiling design (CSG Tree generation)... Rendering Polygon Mesh using CGAL... ERROR: CGAL error in CGAL_Nef_polyhedron3(): CGAL ERROR: assertion violation! Expr: e->incident_sface() != SFace_const_handle() File: /data/OpenSCAD/libraries-mingw64-master/mxe-w64/usr/x86_64-w64-mingw32.static/include/CGAL/Nef_S2/SM_const_decorator.h Line: 326 ERROR: CGAL error in CGAL_Nef_polyhedron3(): CGAL ERROR: assertion violation! Expr: e->incident_sface() != SFace_const_handle() File: /data/OpenSCAD/libraries-mingw64-master/mxe-w64/usr/x86_64-w64-mingw32.static/include/CGAL/Nef_S2/SM_const_decorator.h Line: 326 Geometries in cache: 2 Geometry cache size in bytes: 24496 CGAL Polyhedrons in cache: 1 CGAL cache size in bytes: 0 Total rendering time: 0 hours, 0 minutes, 0 seconds Rendering finished. Could be an OpenSCAD bug? But I have seen STLs which pass Netfabb but still have issues.... ----- Unless specifically shown otherwise above, my contribution is in the Public Domain; To the extent possible under law, I have waived all copyright and related or neighbouring rights to this work. This work is published globally via the internet. :) Inclusion of works of previous authors is not included in the above. The TPP is no simple “trade agreement.” Fight it! http://www.ourfairdeal.org/ -- View this message in context: http://forum.openscad.org/import-2-stl-objects-error-tp12748p13404.html Sent from the OpenSCAD mailing list archive at Nabble.com.