Autodesk has just released the Autodesk 3D Print Utility (A3DP) for free. You can use this free standalone utility when installing Autodesk’s 123D Design, 123D Make, or 123D Catch and selecting the option to install the standalone 3D Print Utility or go to the 3D Print Utility download page: http://apps.123dapp.com/3dprint/install.html. Make sure to close all applications and save all files before installing the utility. I experienced an installer reboot problem that might have only happened to me, but I wanted to make sure if it wasn't that you were aware. Making sure you close applications and save all files is good advice when installing any applications.
The 3D Print Utility optimizes the 3D printing of a model for best results and making it super easy to get a good 3D print by making sure the model is oriented the best way to print and support, healing the model of bad surfaces or holes as your model must be “watertight” closed to print in most cases, and also optimizing the material usage. You can print from within some of the free 123D Apps, or use the stand alone 3D Print Utility to open a STL or OBJ and print them.
In addition to the healing, the 3D Print Utility also allows you to change options like thicken thin regions or hollow the 3D print. It auto-magically adds support material so you to print more complex objects with overhangs like the Delicate Arch model of mine.
For more info on the Autodesk 3D Print Utility check out the 123D Team’s blog post:
Introducing the Autodesk 3D Print Utility