This is work in progress!!! UPDATE: on request a set of STL are uploaded. They are only at BETA stage. Please do not ask features or corrections. Instead edit your copy of the 123D files. A mini electric ducted fan (EDF) designed around the E-flite BL180 - 3000KV brushless motor. Look how small it is. (2s Lipo, 2A continuous, 3A for 10 seconds max.) Main features are: First printed impeller was running without any vibrations!!! Designed in Autodesk 123D. Impeller must be printed with 100% fill for strength. Use support material. My current settings: First layer: 0,25mm Next layers: 0,15mm PLA at 180 deg. C Bed at 57 deg. C "Slow speed" / Cooling fan with open window and freezing outside / tweaking and tweaking and tweaking of all params in Slic3r. PS. You might want to process the STL file in meshlab prior to slicing.