Johnson Polyhedra

thingiverse

Johnson polyhedra are made up of faces in the form of triangles, squares, pentagons, hexagons, octagons, and decagons. There are only 92 such polyhedra. You can create paper models using instructions or print more durable versions with stl files. Check out the netlib library of polyhedra at http://netlib.sandia.gov/polyhedra/. The site includes Johnson polyhedra and provides a way to convert files to openSCAD commands, which output an stl file. A fortran program can be used to convert these files, but note that some errors may occur. These have been corrected by George Hart (http://www.georgehart.com/virtual-polyhedra/netlib-info.html). You will find the 92 scad and stl files in Johnson_Scad_Files.zip and Johnson_Stl_Files.zip, respectively. To print large versions of these polyhedra, it's best to print a hollow structure. Five examples of hollow polyhedra stl files are included along with a sample openSCAD file (hollow_j03.scad). To print smaller models, directly use the stl files or slightly scale them up. Make sure the z-axis is almost parallel to the largest face for optimal printing. Use the "lay flat" and "put on platform" commands in the rotate and move menus, respectively, to position the model correctly. Instructions for making hollow Johnson polyhedra are included in the comments of the sample file. All samples were printed with a raft and without support.