If your motor has an M5 screw to mount the props, you can put these spinners on top to route the air nicely around the motor. It is also nice if you put your copter upside down for maintenance or to (un)mount your battery. Internally, the M5 bolt of your motor fits over a length of 10mm. The bottom 4mm are additionally larger to make room for a nut. So this spinner was designed for motors where you put on props with a nut on an M5 bolt, which then can stand out further up to 6mm above the nut. You can adjust these metrics in the mesh if it doesn't fit. Since the transition from nut to bold when printing layer by layer happens immediately, there should be some support unless your slicing program can handle situations like this very cleverly. I included a version with small internal support which can then be easily be removed with pliers. A blender file is included, but it's only a raw mesh, the support being a separate object.Print the version which includes support, but print it without automatic support, of course. I printed it in 0.2mm layers and a low infill ratio. After printing, you can easily remove the support from the actual spinners with pliers. The internal support structure is 4mm tall.