I have a 3D printer and have experimented with various printing materials, however I would never trust my Phantom to the structural integrity of a 3D printed prop no matter how well designed it was.I was wondering if boat-propeller-style blades would help any? Any 3D modelers out there with 3D printers?
@johnnyu i have the same issue. i hover the bird to ensure all is good then lift up high enough so i can't hear it....when landing, i usually hover above the 'home' point then come straight down - luckily the P3 has higher descent speed. Or sometime i wait for their Air conditioner unit start to take off.....those things are almost as loud as the bird...if not louder.
its not so much me, but my neighbors who might not wish to hear this thing coming and going. just an added tidbit
I found this awhile back and cut it from a previous usage.
I'm sorry I cannot find the link or cite the source at this time:
"There are many sources of prop noise and they have varying levels of significance. The most annoying is the very distinct "shriek" that comes from shocks forming at the tips. Tip speed is a main factor in this noise source.
The airfoil, planform shape, and thickness at the tip are also important since they define the Mach number at which compressibility effects begin to become significant.
So the air does, indeed, accelerate beyond the rotational speed as dictated by these geometric factors and you will often find that keeping the tip speed below about Mach = 0.65-0.70 avoids the onset of shock waves and thus the noise associated with them for most hobby props."
So it seems that altitude, as bbfpv pointed out, is the best way to achieve your goals.