Parametric replacement fan blades

thingiverse

I was inspired by http://www.thingiverse.com/thing:186979 to repair my damaged fans. To achieve this, I re-designed it in OpenSCAD, making a key modification - the fan blades are parabolic curves and have winglets to minimize backflow. Unfortunately, those blade blades were not customizable, which was disappointing since they are too large for my 40x40x10 fans. The dimensions in the file were rough estimates based on my guess of what I believe is the size of my fan. Once I return to the printer, I'll make any necessary adjustments. To date, all source code has been kept up to date at: https://github.com/hyperair/fan-blades I recently made an update and decided that winglets were not a sufficient improvement. Consequently, I decreased blade pitch, removed some blades, and changed the shape of the parabolic curve slightly. Currently, this yields about the same airflow as my OEM fan. One update to make: there was an off-by-one error in one loop that prevented me from achieving perfect symmetry with the part above the print bed. Thanks go out to Kevin for catching this glitch in #reprap. Firstly, you will need to take off any remaining fan blades on your fan hub using a cut off tool. The next step is to grind down these stubs as smooth and level as possible. Take accurate measurements of your fan's outer diameter in millimeters by adding .5 for some clearance space, specifying the new value for 'hub_d". Subtract .5 from this measurement taken on your fan hub for the 'propeller_d'. Next, accurately measure the thickness of your fan, entering the results as your 'blade_thickness'. Rotate your printer so the motor facing away. From here determine whether it spins counter-clockwise with a reading of '-1' or clockwise by inputting '1', saving this data to 'blade_direction'. To print you must select either 0.10mm or some alternative layer height suitable to work for your situation. Please consider printing in solid style so as the layer cannot be supported elsewhere within your build structure due to a voided inner space.