Read all 26 machine reviews in Make:'s Annual Guide to 3D Printing 2015: http://bit.ly/1E9zk17 These test geometries are designed to evaluate specific performance characteristics and motion systems in common low-cost FDM/FFF machines. Traditionally, layer height has been used as a proxy for resolution or quality, but it is a bit of an oversimplification of what is often termed "print quality". The following test geometries individually probe very specific aspects of 3D printer performance in an effort to develop a parametric and quantitative definition of 3D printer quality.  One of the exciting aspects of sharing a standard set of test geometries is that everybody can share their results and learn from this pool of results.  Please post images of individual test geometries printed on your machines using the "I Made One" feature and include your *slicer, layer height, shells, temperature, and print time. Additionally, the test geometries were modeled in Fusion 360 and are designed to be easily modified easily using a small set of control parameters. Source files (.f3d) can be found in the zipped "FDM_f3d.zip" folder. Here's how to evaluate and score these test prints: http://wp.me/p22K2I-1TOt Prints: 1. Dimensional Accuracy 2. Bridging Performance 3. Overhang Performance 4. Negative Space Tolerance 5. Fine Positive Features Performance 6. XY Resonance 7. Z Resonance