I needed 3D printing capability to develop my Propeller Shroud Project

So, I conceived and print another kind of propeller shroud, and I 3D printed it. It is a kit made in ABS, consisting of 9 parts, to be glued around the hub, and screwed for the outer parts.

This shroud can be used as a blade protection, and could interact slightly with the airflow. Curious about the aerodynamics effect of it, the propeller blade tip can be very close to the inner wall.

This was my first 3D printed project, and result can be amazing.

So, I ordered a 3d printer to go on developing my initial shroud project, looking for quite large printing size.

With this capability, all parts (stator/duct, rotor, hub/vanes) can be conceived and printed in an easier way than manual prototyping and hand molding.

The model here is for a 13" propeller, but any size, any kind of arm are possible.

Since several months, my interest in shrouded propeller is increasing, and I started to prototype a shroud.
What are the advantage of a shrouded propeller?
We can list 3 main points:
1 - Increased thrust, compared to the same unshrouded prop. (Possible gain 30% to 100%)
2 - Propeller protection. This adds security and allows to "touch" a wall, by example.
3 - Reduced noise. The propeller tip overpressure/underpressure vortex is encaged.

The prototype is for a 10'' prop, and several pitch will be tested.
The tests consists in comparing the generated thrust, for a given amps (and RPM), between shrouded prop and same unshrouded prop.

If there is an interest, I plan to design a CAD/CAM plastic mold, to produce such shroud in quantity.
The shroud will be in 2 or 4 parts, easy to mount, with a plate connexcting motor and shroud arms.

Here is the ready to assemble shroud.
Diameter is 32 cenitmeters, height is 11 centimeters, weighting 79 grams.

The next step is the shroud/frame/motor assembly.
Two motors will be used in different setup, with a choice a various propellers.
2 blades propellers are not well suited to maximize the effect, so some custom rotor (multi blades) will be conceived.

When the assembly is okay, bench testing will compare thrust (and other aspects) with and without shroud, using different propellers, and custom rotors later.