Four Propellers Left & Right 7-Blade and Left & Ri

Four Propellers Left & Right 7-Blade and Left & Right 8-Blade 2mm shaft hole

My test print went perfect and the fan blades work well moving a lot of air ... the idea is to build an array of small D.C. motors with 2mm shafts on a frame so that there are fans blowing a mass of air through a cardboard box to create a small wind tunnel for small aerodynamic tests including wing sections and small aircraft.  How to track the flow?  Use inscense sticks in strategic positions in front of the test model to see the airflow around the test model.

The motor shaft hole is 2mm but you can drill it out for larger motor shafts as needed.