The problem I noticed with ducted fans is that the ones sold by hobby shops all rotate in the same direction. If someone built a larger diameter ducted fan with both clockwise and counterclockwise props, I think a lot of people would use them for drones. A ducted fan with the same prop diameter as an un-ducted prop is 10-15% more efficient and quieter, so that could make up for the extra weight of the duct itself. The problem is that all the ducted fans out there are designed for airplanes and have too small of a diameter for drones.
You raise great questions regarding using the ducted fan configuration, while attempts in overcoming low efficiency in overall performance. I favor the use of ducted fan over typical quad copters because they are naturally safer with great innovation potential. In my opinion, there are a lot of factors that would solve your issues, most being design. Eventually you will solve your design issues from continued prototype building and seeking advice on awesome websites like DIY Drones.
indeed i do have an idea, check out my blog on laser cut frames, i touched on protecting the blades in my designs but simply expanding the frame wider than the props, but a simple solutin could be turned to if you had the tools, on cheap flying toys sometimes the prop has a circle built int it that means it doesn't have anywhere to hit as the rotors are behind the disk.
The ducted fan doesn't perform nearly as well as the 'typical' DIY Drone quad copter; but it does fly. I attempted to control yaw by having the fans offset and it worked, just not well. Also, the fans are incredibly loud. I've also built the standard propeller quad copter and it is much more smooth and efficient. Here is my concern with props: The reality is that they are dangerous! I've already been hit by props and received stitches. You can't expect them to be flying in every household as-is. This is an area that could be improved. Ideas?
I pursued something like this a few years ago, what ended up being the roadblock was that the ducted fans couldn't translate input changes into thrust changes fast enough to work in this configuration.
Comments
The problem I noticed with ducted fans is that the ones sold by hobby shops all rotate in the same direction. If someone built a larger diameter ducted fan with both clockwise and counterclockwise props, I think a lot of people would use them for drones. A ducted fan with the same prop diameter as an un-ducted prop is 10-15% more efficient and quieter, so that could make up for the extra weight of the duct itself. The problem is that all the ducted fans out there are designed for airplanes and have too small of a diameter for drones.
Josh,
You raise great questions regarding using the ducted fan configuration, while attempts in overcoming low efficiency in overall performance. I favor the use of ducted fan over typical quad copters because they are naturally safer with great innovation potential. In my opinion, there are a lot of factors that would solve your issues, most being design. Eventually you will solve your design issues from continued prototype building and seeking advice on awesome websites like DIY Drones.
indeed i do have an idea, check out my blog on laser cut frames, i touched on protecting the blades in my designs but simply expanding the frame wider than the props, but a simple solutin could be turned to if you had the tools, on cheap flying toys sometimes the prop has a circle built int it that means it doesn't have anywhere to hit as the rotors are behind the disk.
The ducted fan doesn't perform nearly as well as the 'typical' DIY Drone quad copter; but it does fly. I attempted to control yaw by having the fans offset and it worked, just not well. Also, the fans are incredibly loud. I've also built the standard propeller quad copter and it is much more smooth and efficient. Here is my concern with props: The reality is that they are dangerous! I've already been hit by props and received stitches. You can't expect them to be flying in every household as-is. This is an area that could be improved. Ideas?
I like it! apart from not having thrust vectoring it's close to a design I was dreaming up a while back
I pursued something like this a few years ago, what ended up being the roadblock was that the ducted fans couldn't translate input changes into thrust changes fast enough to work in this configuration.
Perhaps this could provide advantages when talking about a VTOL aircraft which transitions into a high speed fixed wing configuration.
Everyone wants a really small footprint with huge carrying capacity, long range, and time on target.
Forget about it.
Efficiency drops by the cube of the airfoil speed;
ducted fans aren't merely inefficient, they are exponentially less effective at providing static lift, run time.
next.
At first, I was concerned about YAW but now, Brilliant adding the angle to the motors. Only issue is the current requirement.
Advancements in all types of drone technology will rise with increased participation in this industry worldwide.
Josh,
Keep up the awesome work.