OpenSCAD uses a cartesian coordinate system, which is unitless. Thus the value 1 in OpenSCAD can be interpreted as 1mm, 1 inch or even 1 light year, depending on your tool and its setting. If your tool does not allow to change this setting, you also can use OpenSCAD to scale and rotate (or mirror) a design in order to target a specific coordinate system. The following example shows how you map a design scaled for a standard device space based on millimeters into a device space using inches and a reversed z-axis. Put all your design code into a module called *mypart* and use this header for export with (F6). > mm2i = 0.0393701; // mm --> inch > mirror ([0, 0, 1]) > scale([mm2i, mm2i, mm2i]) > mypart(); -- View this message in context: http://forum.openscad.org/change-global-coordinate-system-tp19487p19497.html Sent from the OpenSCAD mailing list archive at Nabble.com.