Questions tagged [multirotor]

A flying machine that uses multiple propellers, or rotors, to maintain flight.

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5
votes
2answers
610 views

Will this set up fry my components?

Frame: Carbon fiber 250mm Motors: 2300Kv 2204 Power board: Matek built in BEC’s 12V + 5V FC: CC3D ESCs: HLGRC 30A opto (no BEC) Battery: Turnigy Graphene 14V 75C 4S Receiver: Turnigy iA6B My question ...
8
votes
1answer
76 views

Is there a method to wire a brushless motor to an ESC so it spins in the required direction first time?

So I know that three phase motors will reverse direction when 2 wires are swapped round, or that the direction can be changed in software (such as BLHeli). But is there a method to get it right first ...
2
votes
3answers
50 views

Wired drone using very high voltage?

For those of you who don't know: electricity can be "stepped up" to carry the same amount of power over a thinner wire, over much longer distances with minimal losses. Once the power reaches the ...
6
votes
3answers
106 views

How to determine the lowest safe ESC current rating for a drone build?

I was planning to build a quadcopter and was wondering how I should decide what ESC to get. I'm asking about ESC current ratings. I am building a 7 inch drone using 4s with 2306 1900Kv motors. I have ...
5
votes
1answer
45 views

How to clean dirt out of my miniquad motors?

I accidentally crashed my 250 class quadcopter into the dirt today and got dirt all over it, including into the motors. I managed to clean the dirt off of the frame and electronics, but I have no idea ...
2
votes
0answers
22 views

Does flying a drone close to the ground affect signal quality? [duplicate]

If I were to fly a drone over a large, flat field and there was nothing blocking Line of sight to the drone, would flying at close proximity to the ground impact the FPV video reception? would flying ...
3
votes
2answers
55 views

Do flexible propellers affect multirotor efficiency?

There are a wide variety of materials and methods for making the propellers used on drones. This leads to certain propellers having different characteristics than others. Some propellers are more ...
3
votes
2answers
79 views

How to reduce propeller tip losses?

I have heard that tip losses in propellers can occur when a propeller is highly loaded (when there is a much higher pressure under the prop blade than above it). This can happen with drones that fly ...
4
votes
1answer
55 views

Does the sharpness of a propeller blade affect efficiency?

Some of the propellers I have used on drones have sharp edges (sharp enough that they have cut me) and others have comparatively dull edges. Does the sharpness of the leading edge of a propeller ...
5
votes
1answer
82 views

How do thrust requirements change as a multirotor leaves ground effect?

Assuming either a quadcopter or a hexacopter, is there any published data on how much more energy is expended to escape the ground effect? Is it a function of the thrust being produced to lift the ...
3
votes
2answers
74 views

Is there an advantage to having more LiPo cells in a low-power drone?

A major reason that high performance racing or freestyle drones use LiPo batteries with high cell count (6s rather that 3s or 4s) is so that the voltage won't sag as much. This allows high performance ...
3
votes
2answers
62 views

Determining the mAh of 4S battery for a 3 inch drone

I have a 3" drone frame, flight controller that can take 3S or 4S LiPo, and 1507 4200KV motors. How do I find the right capacity of battery to purchase? Should I purchase 4S 850mAh or 4S 1500mAh? And ...
10
votes
5answers
4k views

Why do most drones have upward facing motors?

Most freestyle quadcopters I have seen are specifically designed to fly with the motors facing upward and have the arms of the drone underneath the propellers like this: As you can see in the picture ...
5
votes
1answer
39 views

What mission planner should I be using for INav?

I'm new to the quadcopter community and am looking to plan my first mission for my drone. As far as I can tell, the recommended mission planner is an Android app? I am hoping there is a good ...
2
votes
1answer
66 views

How do ducted fans impact drone performance?

There are many drones available which use ducted fans as opposed to open propellers. How does a ducted fan quadcopter differ in performance from an open-prop quadcopter? Note: the other question ...
4
votes
2answers
217 views

Putting decorations onto a drone?

I want to jazz my quadcopter up a bit, maybe put some stickers or little sequins. Will these affect the flying capability of the drone, even though they aren’t that heavy? Will this affect balance?
13
votes
2answers
2k views

Is it better to have a bottom heavy quadcopter or a top heavy quadcopter when it comes to a quadcopter stability?

Does it matter where the battery is mounted? Or is it best to have the centre of gravity aligned with the propeller plane where the thrust is generated?
7
votes
1answer
284 views

What should I look for when choosing a battery for my multicopter?

There are many different kinds of battery, many of which have specifications such as capacity, S configuration, P configuration, C rating etc. How do I translate these into knowing what is best for my ...
6
votes
1answer
143 views

How to identify and address multirotor motor overheating

When flying my drone, I often notice my drone motors getting hot after a flight and am concerned that it could explode/blow up. What does a hot drone motor mean? Is this something to be concerned ...
4
votes
1answer
45 views

Where can I find a computational fluid dynamics model of a full quadcopter or multirotor?

I have searched for any computerized graphics visualization of a quadcopter or other multirotor and all I am able to find are a very few models of a single propeller. (Simscale has an example of a ...
6
votes
2answers
315 views

For custom multirotors, what is the most useful method of collecting flight data?

When it is desirable to know exactly what is happening on a multirotor, such as when flight testing a new multirotor concept or design, what measurement equipment and circuit designs are most useful ...
7
votes
4answers
484 views

How does frame stiffness affect a quadcopter?

When choosing a frame for a drone, something I hear mentioned occasionally is how flexible the carbon fiber is. It seems that the general opinion is: more flex in a frame is worse. How would having a ...
13
votes
2answers
656 views

How do laterally folding propellers affect multirotor flight?

There are a number of multirotors on the market which have propellers which fold at the hub, primarily to make storage and transport easier. Centrifugal force keeps the blade extended when the motor ...
13
votes
2answers
2k views

Why do drone propellers have blades with thin chords?

Almost all propellers used for drones have very thin chord length compared to the propellers used for things like table fans or boats which seem to have blades with much longer chord length. What is ...
14
votes
4answers
3k views

Why are larger propellers generally more efficient than smaller ones?

In almost every case, long-range drones use larger propellers than other drones that don't need to travel very far or don't need to fly for very long. I have heard that a major reason for this is ...
8
votes
1answer
105 views

How to visually inspect the magnitude of PID gains?

The defaults in Betaflight generally work very well, but I own and fly very different quads ranging from 2" to 6". It may easily be that there is room for little adjustments I can make with the tuning ...
3
votes
2answers
193 views

How do I calculate thrust for a quadrocopter?

I am designing a quadrocopter style aircraft that uses a 20 inch propeller 1.625 inches in width and has a pitch of 8 inches. How do I calculate static lift / thrust and the dynamic thrust / lift ...
4
votes
1answer
107 views

Why do most multirotors use outrunner brushless motors?

I've noticed that most every quadcopter drone I see uses outrunner BLDC motors like this: Why is that? What unique advantages to outrunners have that make them better than inrunners for multirotors?
4
votes
2answers
55 views

What is a turtle mode?

Could you explain what is a turtle mode? I'm wondering what the use of it is? Does it work on all quadcopters?
5
votes
2answers
71 views

Advantages to having more rotors?

I have a quadcopter drone, is there an advantage say of having a octocopter instead of a quadcopter. Will it improve performance?
3
votes
1answer
105 views

How does a propeller with more blades create more “grip”

I have heard that the more blades a prop has, the more "grip" it has in the air at the expense of speed. How do more blades create more grip but lose top speed?
4
votes
1answer
52 views

What's the purpose of airmode and idle up?

What are airmode and idle up and what do they do improve my freestyle flights?
9
votes
5answers
136 views

How to clean a drone?

I was just flying my drone when I crashed in some tall grass and there are now a bunch of grass bits all over the drone. How can I clean the drone without damaging it?
4
votes
1answer
33 views

What is RPM filtering in Betaflight?

I've seen a lot of buzz lately about the supposed advantages of using the RPM filtering option introduced in Betaflight 4.1. What is it and how does it improve inflight smoothness?
15
votes
6answers
149 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 ...
10
votes
2answers
115 views

How hot is too hot when it comes to multirotor motors?

I hear this question asked all the time. Are my motors getting too hot? How hot is too hot for motors to get? Anyone have a great way to answer this question, possibly with some temperatures? I ...
13
votes
3answers
96 views

What does Feed Forward do and how does it work?

PID tuning involves P, I and D gains to help the quad follow RC commands. Whenever there is an error, P would "push" the quad to reduce the error. So how does Feed Forward come to play?
9
votes
2answers
62 views

One motor on quadcopter broken

I have a small quadcopter and I realised one of the motors does not turn electronically, meaning it can't fly properly. There is no visible sign of something stuck in the motor, like some string or ...
9
votes
4answers
106 views

How do I pick my gear when getting started with FPV multirotors?

There are a large number of beginner and starter kits out there for people looking to get into multirotor FPV flying, all touting their various advantages over the competition. What should I look for ...
19
votes
4answers
518 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. ...
9
votes
2answers
75 views

Full throttle oscillations

When I give full throttle with a full 4s battery I get vibrations. After a while of flying the vibrations disappear. Everything is fixed (no loose parts) Filters are on 1x multipler. RPM filters are ...
15
votes
4answers
151 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 ...
4
votes
1answer
34 views

What is a ground loop and how does a common ground reduce video noise?

To reduce video noise, it is often recommended to add a common ground between VTX and camera to avoid ground loops. What is a ground loop, how does it add video noise and how can a common ground ...
7
votes
1answer
107 views

Why do 48KHz ESCs increase flight time?

I was looking at ESC settings for whoops/toothpicks and have seen how the 48KHz JESC firmware can increase flight time. Why is this? Thanks!
9
votes
1answer
79 views

Why was 32kHz gyro sampling removed from Betaflight?

For a while, the BetaFlight multirotor firmware supported 32kHz gyroscope polling, but now that feature has been dropped in favor of 8kHz being the highest polling rate. Does anyone know why this was ...
18
votes
1answer
266 views

Why are most multirotors built with an even number of rotors?

The most common types of multirotor are quadcopters, hexacopters and octocopters (with four, six and eight rotors respectively). Are there scientific reasons why most drones built with an even ...