Home built ducted fan

[Clement]

Hello guys. Please help. I am in a low resource setting and dont have access to ducted fans to purchase so i need to build one myself. I have a small motor from a small infrared rc helicopter which i intend to use to power the ducted fan. Please I need answers to the following questions;
1. How many blades in a ducted fan will produce the most thrust
2. What design of blades i.e. large surface area vs small surface area will produce the most thrust. By surface area i mean whether the blades should be thin like those in a turbofan jet engine or fat like in a ships screw
3.What angle of attack of the blades will produce the most thrust, is it 45 degrees?
4. I would like the ducted fan to be not more than 3cm in diameter.
5. Please any ideas on how i could build this ducted fan or any links to websites that provide useful info will be appreciated,

Guys please reply, please help an aviation enthusiast.

Thanks so much guys.

 

[foamtest]

I would say that your best bet is to see what size our motors are, if they are seven millimeters across (I’m pretty sure that’s how they’re measured then this plan would work, if not then disregard) I would get a tiny whoop frame and props and use that as an edf. I hope this helped!

 

[Clement]

Thank you.

 

[Clement]

I just got an idea guys. I will buy a nano drone and use the 4 motors and fans to build 4 ducted fans by just creating a duct for the fan motor units and then placing two under each wing as i am planning to build a 4 engined airliner. However I dont know if these will provide enough thrust for the plane. The plane should be about 60cm long and will be made from styrofoam trays. The drones have 2 bladed fans per motor, i dont know if these will provide sufficient thrust as most ducted fans i see have at least 3 to 4 blades. What do you guys think. Guys please please respond. I'm counting on you guys as i dont know much about these things. Thanks a lot

 

[Chuppster]

Hmm. How much does the Nano Drone weigh? If it's a "tiny whoop" class drone, it probably weighs 25-30 grams. I would assume it can make about 35-40 grams of thrust total from all of its motors combined, given that it can lift itself and accelerate upward in flight. So, if you can keep your air frame and electronics under 45g you should be safe.

Or you could just do this:

 

[foamtest]

I would say the best way to do this is through trial and error, I have been messing around with using old quad and heli parts to make airplanes and it's all really down to trial and error. All of the control board for these helis and quads work differently from the rest and not too many people that are very familiar with what you're trying to do. I would recommend however to try and build something simple just to learn how the electronics behave under different circumstances. Also please share your troubles and results with us, there is always a community member that can give advice or help.

 

[Clement]

Thanks guys