fan blades

-step 0: take off the rotor

-step 1: Rip off all original blades 

-step 2: sand it up a bit

-step 3: use a hot gun to make the ring on the 3d printed spare blades more flexible

-step 4: use a vice grip to snap it on the rotor

-originally for fan 120*120*25, but you can scale it down for your fan