Yesterday I ordered the multicopter frame for my larger multicopter that I will use for aerial photography and videography. After analyzing my needs I decided to buy a foldable Y6 carbon frame from RC-carbon, along with a servo stabilized carbon camera mount and carbon landing gear.
I have previously written briefly about the foldable flat carbon hexacopter frame that I was planning to buy. At the time the extended Y6 frame was not released.
Multicopter carbon frames
Carbon is ridiculously strong and it’s also very light weight. Compared to aluminum, carbon is a bit stiffer and will not absorb vibrations as well. Carbon will also probably crack if you crash it hard, while aluminum will bend.
But for my needs, I rather have a strong light weight multicopter frame, and then add some vibration dampening where needed. E g the carbon camera mount and the flight controller mount will get some vibration dampening.
Y6 frame vs flat hexacopter frame
I was primarly thinking of two different multicopter frames, both hexacopters. Y6 frame and a flat hexacopter frame. They both have six rotors but still they are very different.
Hexacopter frame pros ans cons
The flat hexacopter frame has some advantages.
+ More efficient. Since no propellers are working in down going air.
+ Keeps altitude while yawing.
+ More stable at equal arm length (but a flat hexacopter frame doesn’t fold as well as a Y6)
- Looks crappy and ugly.
- More weight.
- Smaller field of view because of more arms. Bad for aerial photography.
- Hard to see the orientation when it’s up in the air.
- No redundancy in case of a motor failure.
- Larger when the frame is folded
Y6 frame pros ans cons
The Y6 hexacopter frame has even more advantages.
+ Good looking. Beautiful, gracious and elegant as well as murderous and totally bad ass!
+ Smaller when the frame is folded.
+ Less weight (will partially compensate for the efficiency loss).
+ Larger field of view thanks to fewer arms. Good for aerial photography.
+ Easier to see the orientation when it’s up in the air.
+ Redundancy in case of a motor failure thanks to the coaxial construction.
- Less stable at equal arm length (but it’s easier to have long arms on foldable a Y6 frame).
- Less efficient.
- Loses altitude while yawing.
As you can see, the Y6 frame was the better alternative from my perspective. So eventually I ended up with a foldable Y6 carbon frame. It was extended though, so I would get more stability. I figured that I can handle longer arms because in the air it’s only an advantage, and on the ground I will fold it. The Y6 frame I bought was 1 000 mm, but it’s also available in a 750 mm extended version and a 650 mm standard version.
Propeller workaround for Y6 hexacopter frame
The only disadvantage with the Y6 frame for my purpose is the less efficiency.
Because the lower propellers in the coaxial construction is working in the air flow from they will be less efficient. This also means that when you yaw, the lower propellers less efficiency will make the hexacopter drop altitude.
I’ve been thinking of some workarounds for this.
Some people use a larger propeller size for the lower motors. This will make it more efficient, but the heavier propellers might affect the torque and cause unintended yaw.
The better alternative seems to be using propellers of the same size but a higher pitch. Then the propellers will have about the same weight, but the lower propellers will shove more air.
Depending on what motors I will use I will try something like 10×4.7 for upper propellers and 10×6 for the lower propellers.