I agree, on phone that login stuff was blocking a lot of content... very annoying... I signed up a few years ago, it's free and only requires email for login... that's just an FYI
some stuff on manufacturing, which matches your thoughts
"Advanced additive manufacturing technologies played a large role in Sharrow Engineering’s development process, particularly for model scale validation testing because, and the design-test cycle was accelerated considerably. Currently, casting patterns come from 3D printed waxes, but 3D printing is still not at the stage where it scales to production volumes. The ability to manufacture very precise high-quality propellers is essential to Sharrow Engineering’s testing and manufacturing programs. "
"Traditional investment casting is used for both protypes and production versions of the Sharrow Propeller™. Depending on the application and market volume, Sharrow uses the manufacturing process that makes the right propeller for the right application at best value to the customer. "
--- some captions from the pics of the mfg processes ---
"The MX-1 being made with a 5-axis router from a solid billet of aluminum alloy. "
"CAD-CAM manufucturing with 5-axis routers gives Sharrow Engineering the ability to quickly make one-off prototypes for testing. Hundreds have been made of all different sizes for many different applications during the Sharrow Propeller™’s 7+ year development period, says the company. "
"Production versions can be machined using 5-axis routers if that is the most economical process for the application. "
I found this all interesting as my Data Processing/IT career was with 2 engineering/manufacturing companies