The 3d scan is generally used as a base for your cad model, you don’t print it it directly, you instead replicate the shapes in your cad software, that gives you pretty much infinite precision thanks to NURBS
My guess is that both 3D printed fans and production fans get balanced, but the production fans have an extra bit of design, that makes the profile sail at both a wider speed range, and peaks at a higher speed.
The 3d scan is generally used as a base for your cad model, you don’t print it it directly, you instead replicate the shapes in your cad software, that gives you pretty much infinite precision thanks to NURBS
https://en.wikipedia.org/wiki/Non-uniform_rational_B-spline
you'd probably have to do a bit of fixing on a model to get close
My guess is that both 3D printed fans and production fans get balanced, but the production fans have an extra bit of design, that makes the profile sail at both a wider speed range, and peaks at a higher speed.