This fan is just an experiment and is not intended for long term operations. It moves a decent amount of air but slightly vibrates due to improper alignment and a lack of bearings. I'd like to find a way to alleviate these problems without resorting to any vitamins. The dimensions are in no way optimized for maximum airflow. All fan characteristics were implemented based on countless model simulations done in my head using highly advanced guesstimate techniques. I may of also been distracted by the latest episode of The Walking Dead while performing these specialized simulations.If you are interested in actual Centrifugal Fan design, check out these PDF's: http://www.wesellfans.com/pdf/underStanding-Centrifugal-Fans.pdfhttp://www.ijaet.org/media/0001/5PARAMETRIC-STUDY-OF-CENTRIFUGAL-FAN-PERFORMANCE-EXPERIMENTS-AND-NUMERICAL-SIMULATION-Copyright-IJAET.pdfWhen printing the parts only generate support for the Fan Case. The necessary support for the Fan Blade is already generated in the .stl file.I recommend that you print the case in PLA. The walls suffer from warping when using ABS due to how thin and high they are. You can see these effects in my photos.You will need an appropriate sized motor. The one that I used was just randomly found and has no markings. When you first turn it on, check that the Fan Blade is rotating counter-clockwise. If not, simply reverse the leads.