4 ms·

They're claiming flight time - in the battery section of the infographic it claims "flight times of more than 40 minutes". Tri-blade props are not the most eff

They're claiming flight time - in the battery section of the infographic it claims "flight times of more than 40 minutes". Tri-blade props are not the most efficient - we use them in racing applications because we want to generate maximum thrust and we don't need more than around 2-3 minutes per battery but we wouldn't use them in an aerial photo rig where we want long flight times - 2 blade props would be the go to. Also the pitch of those blades in the photo are quite aggressive. I wonder if they have different configurations - as photographed I can easily believe the 50mph top speed with small but high kv (fast but inefficient) motors but I'd expect a different configuration for longer flight times. From the photo it looks like the battery compartment is shaped for 2 cylinders, its about the right dimensions for 2x 18650 cells but it's impossible to say for sure. That would give up to 8000mah of 3.7v (1S2P configuration) or 4000mah at 7.4v (2s1p). They could be using different chemistry though, e.g. I usually fly LiHV cells which have a higher nominal voltage in the same pack size & weight - you do get very slightly more watt hours out of those packs (not as much as the numbers would suggest). The given all up weight looks plausible based on the size of what's shown and the weight of 2 cells.

sandworm101 6y ago
In a military context, "flight" can mean "mission". I only suggest that something may have been lost in the language. I find that easier to believe than this thing hovering over a battlefield for 40 minutes.
- simonh 6y ago
  On the other hand if it includes significant landed time as a fixed cam, 40 minutes seems miserably short.
eulers_secret 6y ago
Drone racer here, too! 18650s are amazing as far as power density is concerned. Here's a guy who takes a 3" 1S quad, adapts an 18650 and gets 29 minutes of flight time: https://www.youtube.com/watch?v=BOZStU-QCSc https://www.youtube.com/watch?v=BOZStU-QCSc There's a few others, and in fact I considered doing this myself! But, I'd get bored of slowbelly 'flying' after about 15 minutes. I like to go fast. I completely believe 40mins of flight time if you had actual resources to assign to this. Imagine using the 18650 as the frame and strapping motors to sticks, or other crazy ideas to bring weight down and time up.
arminiusreturns 6y ago
Since you seem to have some expertise in this area, I am going to use the opportunity to ask a bit of a diagonal question I've wondered for a while: I've seen claims about increase in airflow from bladeless fan designs (I know it's a bit of misnomer, as the blades are just hidden) for home applications. Is there a reason bladeless designs haven't been used in the UAV realm? I assumed the claims were just marketing, or the weight increase offsets the effeciency, or something like that, but thought I would ask.
- CraigJPerry 6y ago
  Well out of my wheel house unfortunately but i do know that “air multiplier” marketing speak is called something like the coanda effect. A Tom Stanton video with his coanda effect quadcopter https://m.youtube.com/watch?v=Irp_vnmUWZ4 https://m.youtube.com/watch?v=Irp_vnmUWZ4
- leetcrew 6y ago
  are you talking about ducted fans? if so I've wondered the same thing. here's a plausible answer: https://aviation.stackexchange.com/questions/36726/why-dont-drones-use-ducted-fans/59437 https://aviation.stackexchange.com/questions/36726/why-dont-....
- snovv_crash 6y ago
  The ducting 'shadows' the blade during forward flight, massively reducing efficiency. During hover they can help though.

sandworm101 6y ago

In a military context, "flight" can mean "mission". I only suggest that something may have been lost in the language. I find that easier to believe than this thing hovering over a battlefield for 40 minutes.

simonh 6y ago
On the other hand if it includes significant landed time as a fixed cam, 40 minutes seems miserably short.

eulers_secret 6y ago

Drone racer here, too! 18650s are amazing as far as power density is concerned. Here's a guy who takes a 3" 1S quad, adapts an 18650 and gets 29 minutes of flight time: https://www.youtube.com/watch?v=BOZStU-QCSc https://www.youtube.com/watch?v=BOZStU-QCSc There's a few others, and in fact I considered doing this myself! But, I'd get bored of slowbelly 'flying' after about 15 minutes. I like to go fast. I completely believe 40mins of flight time if you had actual resources to assign to this. Imagine using the 18650 as the frame and strapping motors to sticks, or other crazy ideas to bring weight down and time up.

arminiusreturns 6y ago

Since you seem to have some expertise in this area, I am going to use the opportunity to ask a bit of a diagonal question I've wondered for a while: I've seen claims about increase in airflow from bladeless fan designs (I know it's a bit of misnomer, as the blades are just hidden) for home applications. Is there a reason bladeless designs haven't been used in the UAV realm? I assumed the claims were just marketing, or the weight increase offsets the effeciency, or something like that, but thought I would ask.

CraigJPerry 6y ago
Well out of my wheel house unfortunately but i do know that “air multiplier” marketing speak is called something like the coanda effect. A Tom Stanton video with his coanda effect quadcopter https://m.youtube.com/watch?v=Irp_vnmUWZ4 https://m.youtube.com/watch?v=Irp_vnmUWZ4
leetcrew 6y ago
are you talking about ducted fans? if so I've wondered the same thing. here's a plausible answer: https://aviation.stackexchange.com/questions/36726/why-dont-drones-use-ducted-fans/59437 https://aviation.stackexchange.com/questions/36726/why-dont-....
snovv_crash 6y ago
The ducting 'shadows' the blade during forward flight, massively reducing efficiency. During hover they can help though.