This page provides a list of the various file types that are used in the reprap software toolchain. You may also want to take a look at Useful Software Packages.
AOI filenames end with .aoi
AOI files are the native file format for Art of Illusion. AoI was never intended to be used as CAD software but you will find a lot of reprap files in this format because AoI is an open source app and is easy to use. In the long run though this app is probably a dead end for designing parts.
DXF and DWG
Files ending with ".dxf" (AutoCAD Drawing Interchange Format) or ".dwg" (AutoCAD DraWinG) are popular 2D CAD file formats. Apparently a surprisingly large number of people like drawing things in a 2D CAD system such as Inkscape or AutoCad, then exporting to DXF, then importing to SCAD to extrude the shape into 3D, and then printing the shape.
GCODE filenames normally end with .gcode
IGES filenames normally end with .igs
This is an older open-format CAD file. It has since been superceded by STEP files as of 1995 or so More detail on IGES files can be found in Wikipedia
INO files are for the arduino IDE as of ver 1.0. They used to be PDE files but I guess they changed the file extension because PDE was for the Processing programming language.
Obj files are simple 3D models. Originally developed by Wavefront, it is now a common input format.
PDE filenames end with .pde
- The PLY format is similar to STL in that it is a wireframe mesh representation of a 3D part
Perhaps the most popular fully parametric file format for 3D printers ends with .scad. Typically people use OpenSCAD to gernerate STL files from the scad file.
STL filenames end with .stl, from "STereoLitography" - the format was actually developed for feeding 3D printers.
STL files are an open file standard and are widely used in Computer Aided Manufacturing (CAM) and rapid prototyping. The STL file format is good for printing out parts because it describes a part's surface geometry. Unfortunately, STL files are terrible for doing Computer Aided Design (CAD). They can be imported into CAD applications but are difficult to change. See the link to the article 'CAD vs CAM' in the discussion section below.
STEP filenames normally end with .stp, from "STandard for the Exchange of Product model data"
STEP files are basically the gold standard for translating between different CAD applications. People that do CAD for a living use STEP files because it is an ISO Standard
Discussions about File Formats
- A community specification for an improvement to STL files.
- A community specification for an open 3D file wrapper.
- ""CAD" files vs CAM files - a designer's plea". ... "STLs are to CAD models as a PDF full of photographs of words is to a text file. You can send them both to a printer just fine, but it's a big hassle to fix a typo." ... "the .scad files contain formulas that document what we in the SolidWorks community call "design intent"." ...