3D printing common file types

Overview

STLS and OBJs are file types used for 3D models.
GCode,, X3G and S3G are toolpath files containing instructions for 3D printers.

STL

An STL is a widely-used type of 3D model file. It consists of surfaces made up of triangles. Each triangle has an inner side and an outer side. The outer side is called the “normal.” In a well-formed STL, all the normals face outward and the surface is continuous, with no holes. When a model meets these standards, it is referred to as “manifold.” STLs with normals that face inwards (inverted normals) may be printable, but manifold models are typically considered mandatory for 3D printing.

STLs are compatible with many different 3D modeling programs and have become the standard file type for 3D printable models. SolidWorks®, Rhinoceros®, and most Autodesk® programs will export STL files, and there are free plugins available that will allow you to export STLs from SketchUp®.

OBJ

An OBJ is another type of 3D model file. It is also used by a number of 3D modeling programs, but is used for 3D printing less often than STL. Unlike STLs, where every facet of your 3D model is a triangle, an OBJ can contain both triangles and other polygons. Rhinoceros and some Autodesk programs will export OBJ files, but other programs, including SketchUp and SolidWorks, will require a plugin to export as OBJ.

GCode and X3G/S3G

For MakerBot Replicator 3D printers prior to the Fifth Generation, the MakerBot Slicer turns your 3D model into a set of instructions using a computer language called GCode. The instructions consist of commands that tell the extruders how hot to get, where to move and when to start extruding plastic, commands that control the build platform, and commands for peripheral components, including the LEDs inside your MakerBot. For more information about GCode, click here.



When exporting your print file, MakerBot Desktop automatically converts your human-readable GCode to a more compact, computer-readable format. For the MakerBot Replicator 2 and MakerBot Replicator 2X, and for Original MakerBot Replicators with firmware 7.0 or above, the correct format is X3G. For Original MakerBot Replicators with firmware below 7.0, the correct format is S3G.

from MakerBot