Parametric replacement fan blades

thingiverse

Inspired by http://www.thingiverse.com/thing:186979 to try and fix my many broken fans, I was rather disappointed to note that those fan blades were not customizable, and were too big for the 40x40x10 fans I have. So, I redesigned it in OpenSCAD, with a twist -- the blades are parabolic curves (I might work on trying a NACA airfoil blade profile instead), and have winglets to try to avoid a backflow of air. I haven't tested it yet, and the dimensions I've stuffed into the file are guesstimations based on what I think the fan size is. I'll fine-tune it when I get back to the printer. Sources are kept up to date here: https://github.com/hyperair/fan-blades Update: winglets didn't seem to help it much -- I reduced the blade pitch and number of blades, and added a bit of linearity to the parabolic curve. It seems to give about as much airflow as the OEM fan blades now. Update: Fixed an off-by-one issue in a loop causing the blade to end just above the bed. Thanks to Kevin` on #reprap for spotting that. Instructions Cut off the remaining blades of your fan hub. Grind down the stubs so you get the fan hub as round and balanced as possible. Measure the diameter of your fan hub in mm, add 0.5 for a bit of clearance, and specify that in hub_d. Measure the outer diameter of your fan hub in mm, subtract 0.5, and specify that in propeller_d. Measure the thickness of your hub, and specify that in blade_thickness Check which way your fan spins, with the fan facing you (wind blows away from you, towards the frame). Specify that in blade_direction -- -1 for counter-clockwise, 1 for clockwise. Print with around 0.1mm layer height, or whatever works best for you. The overhang can be tricky, so the lower you go without overheating your part, the better. Solid, because there isn't any area for infill anyway.