Spitfire Propeller designed with Autocad 3D 1:4 model Root hub to fit into spinner: 3.4cm diameter circle. From Root to tip =  375 mm or 14.76 inches Comes in 5 parts, glued together using locttite 406 superglue for plastics You can scale accordingly. Eg, a 1:8 model just divide full scale by 2.  Recommended print settings (tested as per picture) Vertical wall: 2 shells Infill honeycomb/rectilinear 5% Bottom and Top solid layers: 3  Printspeed keep it generally 50mm/s throughout for smooth and sharp print especially at the trailing edge of the blade Estimated 1.75mm filament needed for 1 blade (1:4 scale model) = Between 15meters to 25meters (49ft to 82ft)   Print with PLA to avoid wrapping