Highest scored questions
968 questions
21
votes
4
answers
2k
views
Why do multirotors usually have four propellors?
I've observed that hover-capable drones almost always have four propellers. There are helicopters of course, which have two, but in general, the vast majority of UAVs seem to go with four propellers.
...
- 1,053
21
votes
2
answers
980
views
Is it safe to fly LiPo batteries after they get "puffy"?
Some of my LiPo batteries got "puffy" after a few months. Is it still safe to fly them, or should I safely dispose of them?
- 445
19
votes
3
answers
4k
views
How long can a LiPo pack be kept fully discharged before storage charging?
There is a reason LiPo packs are recommended to be stored at a storage charge. It is commonly known that storing a battery fully charged reduces its capacity and performance. What about storing ...
- 504
18
votes
8
answers
8k
views
What is a good alternative to carbon fibre for a quadcopter frame?
I am making a diy quadcopter and I need a strong and light material for its frame.
Carbon fibre is not available in my area. I have tried aluminium but it's too soft and so needs repairs. What ...
- 259
18
votes
4
answers
7k
views
How does a quadcopter yaw?
I've always wondered how a quadcopter actually yaws, when all propellers are horizontal. I know that two of the motors spins faster, but I don't understand how that generates thrust in the horizontal ...
- 2,674
18
votes
3
answers
5k
views
Why are quadcopters inherently unstable?
I have heard it mentioned that quadcopters are inherently unstable and only become stable due to control. What does inherently unstable mean in this context, and why are quadcopters inherently ...
- 5,802
18
votes
2
answers
8k
views
Why do the motors on my drone keep spinning up and max out when I run up the throttle on my radio on the bench?
When I test my drone for the first time and I run the throttle up form my remote with the props off the motors keep spinning even when I bring my throttle back down. Will my quad flip out if I put the ...
- 1,250
17
votes
4
answers
3k
views
What's the advantage of props in VS props out?
I've heard that the quad will handle better if you reverse the propeller direction (props out), but is the difference noticeable? Especially for a relatively new pilot. Should you use props out from ...
- 2,674
17
votes
3
answers
730
views
How do you figure out which motors to use for your UAV?
There are a ton of electric motors on the market. Is there a mathematical formula or some other means of figuring out which size of motor you will need for your airplane, helicopter, or drone?
- 281
17
votes
1
answer
440
views
Why are most multirotors built with an even number of rotors?
The most common types of multirotors are quadcopters, hexacopters and octocopters (with four, six and eight rotors respectively).
Are there scientific reasons why most drones are built with an even ...
- 588
16
votes
2
answers
3k
views
Flying a UAV with a banner?
I want to attach a banner to a UAV like this:
I have two questions:
Firstly, is it even possible to fly a UAV like this with the banner visible?
What sort of design considerations would I have to ...
- 752
16
votes
2
answers
3k
views
What does it mean for SBUS to be an inverted protocol?
I've heard talk about how F4-based flight controllers can't natively support the SBUS receiver protocol without special circuitry. What does this mean and what hardware is needed to invert an inverted ...
- 6,073
16
votes
3
answers
258
views
Storing drones during the winter
Up here in Canada, it can get kinda cold during the winter. And just because of where I tend to use my drone, it can be easier for me to store it in an outdoor (dry, but unheated) shelter than to haul ...
- 1,053
15
votes
2
answers
6k
views
Is owning, but not flying, a drone in Germany illegal?
I live in Germany but I travel a lot around the world; my new hobby is aerial photography, for this I am considering buying a drone.
Since Germany has some rules about drones, can I have a drone in ...
15
votes
6
answers
1k
views
How does one hold the motor bell still when tightening prop nuts?
Almost all of the brushless motors used in hobby-grade multirotors have a single threaded shaft and rely only on friction between the propeller and motor to keep the prop from slipping. This means ...
- 2,997