What software can you use to make printable 3D models?
Tinkercad
Tinkercad from Autodesk is a user-friendly program that's great for beginners. Users can make their own objects without the need to download software. You either need to create a free account or sign in using Facebook. This web-based software allows you to create your own object or customize/personalize preexisting .STL files found online.
*Note- this software default setting is in millimeters so opening a simple conversion table may help if you need something to be a certain size.
SketchUp
While it looks like architectural design software, there is more to this program than that. This easy-to-use and highly rated free software is one of the best ways to create 3D objects. While this application does focus on creating architectural design, interior design, and engineering projects, the user-friendly software can still be used to create everything and anything as well as edit preexisting objects. SketchUp models can be exported as an .OBJ file, which can then be converted to a .STL file using MeshLab or printed as is. We do recommend that it is converted to a .STL file to make it easier to print.
Blender
Blender is a free professional 3D computer graphics software product used for creating animated films, visual effects, art, 3D printed models, interactive 3D applications, and video games. If you are new to computer-generated imaging software or creating your own 3D object, this software has a high learning curve and might be difficult to use. But it’s one of the best out there and will be able to do more with this than many other options.
Where can I find existing 3D models of objects?
Printables and YouMagine are repositories of 3D models by 3D designers from all walks of life and backgrounds. These two websites offer some of the largest gathering of created objects for people to print for themselves. Most of these files export as a .STL or an .OBJ file.
Cubehero and Bld3r are other places to find premade objects like Printables and are slightly smaller and focus more on the mechanical elements and products that the 3D printer can produce.
The NIH 3D Print Exchange allows for searching, downloading, and sharing biomedical 3D print files, modeling tutorials, and educational material. If you’re looking for anything relating to biology or chemistry in the broadest terms then this is the perfect place for you to find 3D models. There are lots of options to export your file as so make sure that you select either a .STL or .OBJ file.
NASA 3D Resources has a growing collection of 3D models, textures, and images from inside and relating to NASA and space exploration. Some of the files are able to be exported as an .OBJ file but before downloading a file make sure that it is either a .STL or .OBJ file.
Smithsonian x 3D is a project to share 3D models developed from scans of their diverse collections. Not all of the collection is available for download but some of the objects are. In order to download an object from their collection you must either log in or register as a user of the site.
What is mesh repair?
Mesh repair is one of the last steps toward finalizing a 3D model to be printed. After you have designed a 3D model, or acquired one from a website like Thingiverse, it is wise to put the .STL file through one of the mesh repair programs below to fix mistakes. Some design programs also have mesh repair functions included. The geometry of a 3D model is made up of a mesh of small triangular planes. Holes, gaps, overlaps, or other errors in the construction of the mesh can potentially cause failed prints. Mesh repair programs can automatically find these small imperfections and clean them up. In other words, this will make your model water tight, or "manifold," and ready to slice. If you attempt to slice a non-manifold model in Ultimaker Cura, the program should notify you and highlight the areas in need of repair.
Autodesk Netfabb is a powerful tool that is easy to use. The full version of the software requires a premium subscription but there is a 30 day free trial. In addition to fixing mesh errors, Netfabb can orient and hollow out your model to help it print efficiently and use less material.
Meshmixer from Autodesk is free and highly versatile. It has an easy to use auto-repair function and also allows you to make a new model from scratch. You can read an in-depth tutorial of Meshmixer's many uses here
Meshlab is an advanced tool for more experienced users. In addition to basic mesh repairs for 3D printing, Meshlab is also specialized for processing unstructured meshes from 3D scanned objects.