Joshua, good explanation on prop size. With respect to the 10" prop size drone, you mentioned a 10" has a lower centralized mass. This is also called polar moment of mass and you are correct, it is critically important in getting an aircraft to change direction. The more the mass is centralized around the center of gravity, the less force is required to change direction. Also, you mentioned that 10" frames have tendencies to vibrations. One of the analyses Chris Rosser does is modal analysis. He considers the vibrations the motors create and he then uses that as an input in a modal analysis to determine if the frame is pushed to a resonant frequency by the motors. Our community can run modal analyses with Fusion360. This is one reason I love FPV! We get to learn so many engineering disciplines! Dave Messina
Bardwell idk if you will see this but youve taught me so much already in the drone hobby and i really appreciate all you do thanks for helping us noobies out
What people, especially quad people, tend to forget is, that your prop blade is essentially a wing with an airfoil. And those airfoils have a sweetspot in speed. The faster they go, the more likely you have a laminar flow separation bubble on top of your blade. Therefore, if your blade tips start to reach .8 mach, transsonic speeds, they get brutally inefficient. On top of that, nobody exactly knows how that airfoil reacts in supersonic airflow. And people tend to forget that prop blades have airdrag, too. Airdrag quadruples with speed. So, all in all, if you can go bigger with your props, do it.
Same here. I started on a DJIU FlameWheel, which I then upgraded with a TBS Discovery kit. I still fly a 10" based on an old discontinued Flight frame.
Disk loading. That's what make it more efficient. The bigger the prop for a given AUW, the lower the disk load on the prop. Lower disk load = better efficiency.
The most part of the higher efficiency comes from the fact that if you double the speed of a thing (like an air molecule) from v1 -> v2 you have to quadruple the energy you put into accelerating it. By doing so you have doubled your thrust using 4 times the energy. But if you move two molecules instead of one at the speed v1 you also have doubled your thrust but only doubled the consumed energy That’s basically it.
I like to think of the advantage of scaling up your drone as "diluting" the payload(which is ideally a non-variable weight) in the overall weight of a drone. If I maintained the exact same Power-To-Weight ratio and double my overall weight, the static payload is a smaller percentage and thus easier to haul efficiently. Naturally, more weight has more inertia and everyone understands that heavy things take a minute to accelerate/turn/stop
When I ordered all the parts for my first drone which was a 7 inch, I ordered different soldering irons to try out and I ordered extra m2 and m3 screws and m2 and m3 stand off kits and even like threadless m2 m3 m4 m5 m6x5, 10, 15, ect. Of these nylon bushings cause I really wasn't sure what I'd need😅 got different plugs too a bag of xt60 and xt30s as well as jst plugs which had to use once when my battery balance lead got smacked by my prop and broke it. Easy fix when you have the parts already
I have the gep rc mark 4 10 inch frame it's quite good with arm braces and chunky arms like 7mm... props is where you don't want to skimp. I only will run gemfast or hq nothing else. I've tried just about all of them. Cheap props make crazy vibrations so don't even try and a great bunch of quality blue jay settings don't hurt either. Yes I'm running 8bit for my 4-1 on my ten inch!!
Is it any purpous to go from mobula 24 frame, to bigger props and keep the 300 batt. Or are 31mm props optimized for 300mah batt... In this case, or is it instead more preferable to try to make the mobula 24 more light..
[Li-Ion, Low Prop Pitch on a larger disk, on Bi-Blades and less Dry weight] =efficiency [Run High-C Li-Po, and do the opposite of for speed, and power, with the exception of a low dry weight.] I can think of a good reason to raise the dry weight if I did not need to. >>Stuff I did: I have found that in going for efficiency, bigger props help but only if I go with a very low pitch. Also, bi-blade of the same diameter and pitch have been more efficient than tri-blade, and the higher the number of blades, the less efficient it becomes. > all else equal, less dry weight means more flight time, but for the same dry weight, and bigger battery of the same voltage gets more flight time. (as the battery weight increases, light characteristics change, so usually there's a sweet spot for each drones's use case) With efficiency as a main objective, LI-Ion is the answer. || You can probably take these notes from my experience and form them to your objective, whether it be speed, agility, flight time, or a flavor in between.
Actually, Ag Drones only fly about 7-8 minutes at max weight. The max weight determines the payload so the battery size is dictated by the amount of product that can be carried. When the bird comes back for a product refill, the battery is swapped too, every time. These batteries are charged at a rate that allows a full charge as fast as it's used.
I mean for a 10" frame it's much more acceptable to have this kind of design than for a 5". I would most fly this on missions where there is coming home or losing the qwad but no crashing and repairing.
Ease of arm replacement seems less important for a 10 inch. You're not building this unless you're already a skilled pilot, and you're not bando bashing or aggressively freestyling a 10 inch.
HaHa.. so true. My first frame was a 10" Lumenier QAV-RXL-2. That was three years ago, and many 3 and 5inch drones, a 7" cruiser, have won my attention. And the QAV-10" is still hanging on my wall, slowly collecting parts that may or may not be the final build, and it waits for me to decide its purpose in the sky. Maybe this will be the year lol
Here's an idea for the frame guys......why not have AI design the frame with the "Evolved Structures" method? 3D printed frames to sell or as a DL file for a fee. Either way, the results would be worth a go.
Difference between 2 inch, 7 inch and 10 inch convinced me to order 13 inch. I have a lot of experience flying micro, 150, 450, 550, 600, 700, 800 class RC helicopters. Wind resistance, stability, weight to trust ratio, long flight times are woth it. In 2013 there were three fatal accidents caused involving 700 class helis (two pilots, one spectator's child). It influenced my way of flying. Since then for 11 years I did not notice any fatal or serious accidents. In my experience 700 and 800 helis are FAR MORE reliable and less prone to malfunctions in flight and in case of failure much easier to control in autorotation. Safety first. Even 2 inch is able to cut skin pretty hard. Considering statistics RC hobby is EXTREMELY safe. I ride motorcycles.There are thousands of fatal accidents involving motorcycles each year. Walking is more dangeros activity than RC hobby. People die due to accidents while walking, falling on slipery surface. I love flying helis and planks, biplanes in strong wind. Dynamic soaring gliders did reach speeds over 900km/h 600 mph. Kwads are awesome due to flight controllers. I am enthusiastic about Rotorflight in RC helis. 10 inch even only on 4S liion Ampace JP40 4000mAh can fly for over 20 miutes. I can put 6S2P in it. Use telemetry to monitor currents drawn. 10 inch can easily draw more than 80A on 4S. I did not test 6S yet. Small kwads are great for free style and racing. Bigger ones10-15 inch are more suited for long range endurance even if some guys race them. Flying exerience is different with bigger kwads. Live in general is fatal sexually transmited disease. Let's have some fun before we all inevitably die.
Big props give you more trust at lower KV. But smaller props at higher KV give you more speed. Its old, no nuclear science. Everybody that is in RC for years know that...
Joshua, good explanation on prop size. With respect to the 10" prop size drone, you mentioned a 10" has a lower centralized mass. This is also called polar moment of mass and you are correct, it is critically important in getting an aircraft to change direction. The more the mass is centralized around the center of gravity, the less force is required to change direction. Also, you mentioned that 10" frames have tendencies to vibrations. One of the analyses Chris Rosser does is modal analysis. He considers the vibrations the motors create and he then uses that as an input in a modal analysis to determine if the frame is pushed to a resonant frequency by the motors. Our community can run modal analyses with Fusion360. This is one reason I love FPV! We get to learn so many engineering disciplines! Dave Messina
Bardwell idk if you will see this but youve taught me so much already in the drone hobby and i really appreciate all you do thanks for helping us noobies out
Chris should make a truss frame 5" bando basher for no reason other than to be a troll. 50 security head screws to remove the top plate
What people, especially quad people, tend to forget is, that your prop blade is essentially a wing with an airfoil. And those airfoils have a sweetspot in speed. The faster they go, the more likely you have a laminar flow separation bubble on top of your blade. Therefore, if your blade tips start to reach .8 mach, transsonic speeds, they get brutally inefficient. On top of that, nobody exactly knows how that airfoil reacts in supersonic airflow. And people tend to forget that prop blades have airdrag, too. Airdrag quadruples with speed. So, all in all, if you can go bigger with your props, do it.
Had to watch this. My first quad was a 500mm kit, I flew 10 and 11" props. I was like, oh no, are we going backwards!
Same here. I started on a DJIU FlameWheel, which I then upgraded with a TBS Discovery kit. I still fly a 10" based on an old discontinued Flight frame.
Mine also.... a stingray 500
Disk loading. That's what make it more efficient. The bigger the prop for a given AUW, the lower the disk load on the prop. Lower disk load = better efficiency.
The other aspect is not just to carry more weight more efficiently, but often it's due to a filming requirement for a higher cruising speed.
Good point.
The most part of the higher efficiency comes from the fact that if you double the speed of a thing (like an air molecule) from v1 -> v2 you have to quadruple the energy you put into accelerating it. By doing so you have doubled your thrust using 4 times the energy.
But if you move two molecules instead of one at the speed v1 you also have doubled your thrust but only doubled the consumed energy
That’s basically it.
I like to think of the advantage of scaling up your drone as "diluting" the payload(which is ideally a non-variable weight) in the overall weight of a drone. If I maintained the exact same Power-To-Weight ratio and double my overall weight, the static payload is a smaller percentage and thus easier to haul efficiently.
Naturally, more weight has more inertia and everyone understands that heavy things take a minute to accelerate/turn/stop
When I ordered all the parts for my first drone which was a 7 inch, I ordered different soldering irons to try out and I ordered extra m2 and m3 screws and m2 and m3 stand off kits and even like threadless m2 m3 m4 m5 m6x5, 10, 15, ect. Of these nylon bushings cause I really wasn't sure what I'd need😅 got different plugs too a bag of xt60 and xt30s as well as jst plugs which had to use once when my battery balance lead got smacked by my prop and broke it. Easy fix when you have the parts already
I have the gep rc mark 4 10 inch frame it's quite good with arm braces and chunky arms like 7mm... props is where you don't want to skimp. I only will run gemfast or hq nothing else. I've tried just about all of them. Cheap props make crazy vibrations so don't even try and a great bunch of quality blue jay settings don't hurt either. Yes I'm running 8bit for my 4-1 on my ten inch!!
Is it any purpous to go from mobula 24 frame, to bigger props and keep the 300 batt.
Or are 31mm props optimized for 300mah batt...
In this case, or is it instead more preferable to try to make the mobula 24 more light..
[Li-Ion, Low Prop Pitch on a larger disk, on Bi-Blades and less Dry weight] =efficiency
[Run High-C Li-Po, and do the opposite of for speed, and power, with the exception of a low dry weight.] I can think of a good reason to raise the dry weight if I did not need to.
>>Stuff I did:
I have found that in going for efficiency, bigger props help but only if I go with a very low pitch. Also, bi-blade of the same diameter and pitch have been more efficient than tri-blade, and the higher the number of blades, the less efficient it becomes. > all else equal, less dry weight means more flight time, but for the same dry weight, and bigger battery of the same voltage gets more flight time. (as the battery weight increases, light characteristics change, so usually there's a sweet spot for each drones's use case) With efficiency as a main objective, LI-Ion is the answer. || You can probably take these notes from my experience and form them to your objective, whether it be speed, agility, flight time, or a flavor in between.
It’s fun, I see potential for fun in my 13” to
I had good luck building on an Aliexpress Apex Evo 10" frame. I know it's a clone, but it flies well.
XL10 ... I fly the XL10.. it's cool...
Planes don't even need a motor to fly. The fastest RC is a dynamic soaring glider at 564 mph
Actually, Ag Drones only fly about 7-8 minutes at max weight. The max weight determines the payload so the battery size is dictated by the amount of product that can be carried. When the bird comes back for a product refill, the battery is swapped too, every time. These batteries are charged at a rate that allows a full charge as fast as it's used.
The GepRC Pulsar LR10 seems like a good option too
I mean for a 10" frame it's much more acceptable to have this kind of design than for a 5".
I would most fly this on missions where there is coming home or losing the qwad but no crashing and repairing.
I fly the geprc 4, and the aliexpress mark 4 that most of russia and Ukraine use, they're essentially the same, but the aliexpress frame is only $20.
Ease of arm replacement seems less important for a 10 inch. You're not building this unless you're already a skilled pilot, and you're not bando bashing or aggressively freestyling a 10 inch.
HaHa.. so true. My first frame was a 10" Lumenier QAV-RXL-2. That was three years ago, and many 3 and 5inch drones, a 7" cruiser, have won my attention. And the QAV-10" is still hanging on my wall, slowly collecting parts that may or may not be the final build, and it waits for me to decide its purpose in the sky. Maybe this will be the year lol
Here's an idea for the frame guys......why not have AI design the frame with the "Evolved Structures" method? 3D printed frames to sell or as a DL file for a fee. Either way, the results would be worth a go.
I don't know why, but for a 10" I'd rather live with plastic arms, like the old TBS Discovery...
Baba Yaga needs bigger props.
Difference between 2 inch, 7 inch and 10 inch convinced me to order 13 inch. I have a lot of experience flying micro, 150, 450, 550, 600, 700, 800 class RC helicopters. Wind resistance, stability, weight to trust ratio, long flight times are woth it. In 2013 there were three fatal accidents caused involving 700 class helis (two pilots, one spectator's child). It influenced my way of flying. Since then for 11 years I did not notice any fatal or serious accidents. In my experience 700 and 800 helis are FAR MORE reliable and less prone to malfunctions in flight and in case of failure much easier to control in autorotation. Safety first. Even 2 inch is able to cut skin pretty hard. Considering statistics RC hobby is EXTREMELY safe. I ride motorcycles.There are thousands of fatal accidents involving motorcycles each year. Walking is more dangeros activity than RC hobby. People die due to accidents while walking, falling on slipery surface. I love flying helis and planks, biplanes in strong wind. Dynamic soaring gliders did reach speeds over 900km/h 600 mph. Kwads are awesome due to flight controllers. I am enthusiastic about Rotorflight in RC helis. 10 inch even only on 4S liion Ampace JP40 4000mAh can fly for over 20 miutes. I can put 6S2P in it. Use telemetry to monitor currents drawn. 10 inch can easily draw more than 80A on 4S. I did not test 6S yet. Small kwads are great for free style and racing. Bigger ones10-15 inch are more suited for long range endurance even if some guys race them. Flying exerience is different with bigger kwads. Live in general is fatal sexually transmited disease. Let's have some fun before we all inevitably die.
Big props give you more trust at lower KV. But smaller props at higher KV give you more speed. Its old, no nuclear science. Everybody that is in RC for years know that...