Questions tagged [motor]

An electronic component that creates torque (rotational force) when electricity is applied.

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1 vote
1 answer
196 views

How to choose the most efficient (thrust per watt) motor+propeller setup for a drone?

I'm designing a quadcopter weighing around 250 grams, while maintaining a thrust-to-weight ratio of 2:1 Optimize: Maximize the thrust-per-watt for the motor+propeller pair Constraints: weight of each ...
2 votes
2 answers
57 views

Motor voltage, kv, and battery weight saving

I would like to ask abt motor and prop size and efficiency. So I was thinking to get either some 2203.5 motor with 1600kv wingspan of about 1,6m and 16x5 prop(prop lenght of 25%of wingspan), however ...
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0 answers
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PIXHAWK 2.4.8 | EMAX Formula Series 45A ESC | No motor is rotating

I'm building S550 Hexacopter from a combo kit. I've made all the connections correctly. I've calibrated the ECS individually & motors run without any issues. But when I arm the drone to test all ...
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1 vote
1 answer
28 views

Is there a calculation to find what motor is required for a specific propeller?

So I am going to be running 20x5.5 carbon fibre drone propellers at 10,000 rpm maximum and I cannot find out which motor I need. I have been scouring the web for weeks and I have given up and I am ...
1 vote
1 answer
443 views

How to calculate lift for multiple rotors?

So I know that $L = \frac{1}{2}​ρv^2AC_L$, but if I want to find the lift for a three-blade helicopter, do I just multiply by 3 or what? Let's say I have a 700mm rotor at 61mm wide, would it be: $L = ...
3 votes
1 answer
506 views

Motor doesn't work, ESC doesn't calibrate

After I figured out why SAFE never turned off, now I'm stuck because my motor won't spin and I can't enter calibration mode of the ESC. After turning on the plane, it does three startup beeps in ...
2 votes
1 answer
65 views

quadcopter motor spinning with resistance and not as freely as other motors

I haven't completed the assembly of my quad but I noticed one of the motors was not spinning as freely as the other 3. It seems like the top spinning part is scraping against the bottom fixed plate ...
6 votes
2 answers
140 views

What is the advantage of using more motors?

I am at the beginning of a drone project, which will have a 25 kg MTOW, and I am analyzing whether I use four, six or eigth engines. Is there a good advantage of using more motors or does it really ...
6 votes
1 answer
91 views

Help with finding a motor to rotate the plane of a propeller

I don't really know if this is related to this community but it's for a drone so it's worth a shot. I'm looking for some sort of motorized hinge or a motor that can move a propeller on the Y-Axis, a ...
7 votes
2 answers
174 views

Proper rotor fastening (Nyloc nut)

I am trying to figure out how to properly fasten my rotors on my quadcopter. I am pretty sure the nuts are Nyloc, but here is a picture for reference: I read online in many places that you should ...
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5 votes
0 answers
57 views

High pressure RC fuel pump

How many PSI do the best (electric) fuel pumps have? For RC jet turbines I found 12 bar the highest. Are there any better?
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5 votes
1 answer
84 views

My esc cuts the motor when I move control surfaces a lot

I finally built my plane and started testing it on my workbench. If I moved the servos a lot (using my transmitter), the motor would cut out, the ESC would play a tone similar to when I first turn it ...
4 votes
1 answer
589 views

How do I attach a propeller to this motor?

As many of you already know, I am getting into RC planes. I went to my hobby shop today and bought a motor and some props, but I can't figure out how to attach a propeller to the motor. Unlike what I'...
8 votes
2 answers
198 views

How to keep my prop from flying off my motor?

After finally getting every piece on my plane to work, another piece decided to be a problem. Great. My problem is pretty much already summed up in the title, my prop keeps flying off my motor, and I ...
5 votes
1 answer
449 views

Eliminate effect of Vibrations on IMU

I am testing pitch orientation correction of Quadcopter and ended up in a issue. I have a test setup with one degree of freedom to test orientation correction. I have fixed the drone to the setup and ...
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5 votes
1 answer
114 views

Estimate safe ESC curerent for 4108 600kv motors?

Is there a way to safely guess what current ESC's will need to be with this motor (or any motor in general)? The motors are rated 23A in the table, but that's only with a 4s; I might use a 6s in the ...
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5 votes
2 answers
1k views

Can motors be "too big" for any reason?

I'm wondering, what would make a certain motor "too powerful/large" for a build? Could software/firmware of FC/ESCs be a problem? The only thing I could come up with is strength of the frame ...
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4 votes
1 answer
253 views

Motor size and Kv advice for ZD550?

I'm building my first drone out of the ZD550 frame. Most of the extra weight would be from a small gimbal like this (180g) and a gopro hero 4 (83g). What kv/size of motor would be ideal for this ...
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5 votes
2 answers
2k views

Motor output limiting

Can you configure your motor output limit on betaflight or DJI goggles? I know you can do it through the fatshark goggles, but I do not have parts to build a drone, so I am asking before I get 2700 ...
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7 votes
1 answer
160 views

How can I run 2207 2450Kv motors on 4S with 7” props?

I’m looking to use some spare motors I have to build a 7” rig. The problem is that they are 2450Kv, and I don’t want to burn out my other components. As I understand it, if I set a motor output limit ...
5 votes
2 answers
92 views

Does motor KV requirement scale linearly with voltage?

There have been myriad questions regarding motor KV, such as this one. Many of these come close to answering my question, however none have given me a definite answer. If I am picking motors for a ...
4 votes
3 answers
205 views

How useful is knowing the torque generated by a motor prop combination?

I'm designing a series of small drones for use in a swarm configuration in combination with terrestrial / marine / submarine robots. As part of the process, I've designed a test rig to measure the ...
6 votes
1 answer
1k 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 ...
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4 votes
1 answer
56 views

Modeling heat build-up in air-cooled outrunners

I'm creating a thermal model for heat build-up in my outrunner motors. So far, I haven't found any online resources that discuss this. Here is the basic equations for forced convective transfer: <...
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4 votes
4 answers
529 views

How should one chose the correct motor KV for a build?

For a 5 inch, 4S build, the general advice is to go 2300-2750KV. For the same size but 6S, it should be ~1800KV. However the same motors could be used on a 4S 7 inch quad. And all of this scaling ...
15 votes
6 answers
599 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 ...
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10 votes
2 answers
780 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 ...
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5 votes
5 answers
455 views

What affects the total flight time for a drone?

What factors would affect a drone's flight time? Battery capacity? Weight? Anything else?
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4 votes
2 answers
114 views

Differences between brushed and brushless motors - advantanges and disadvantages of each

When buying a drone I have 2 options to consider: brushed and brushless motors. Are they much different from each other? Does one have advantages over the other?
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3 votes
2 answers
449 views

How to tell if you have a brushed or brushless motor?

I understand there are 2 main types of motors: brushed and brushless motors. How can you tell visibly what type of motor you have without researching/reading the manual?
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9 votes
2 answers
1k 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 ...
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8 votes
3 answers
166 views

Why does a brushless drone fly longer?

I have noticed that drones with brushless motors fly longer than those with brushed motors. Why are drones with brushless motors able to fly for longer amounts of time?
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4 votes
3 answers
706 views

Why do higher voltage batteries need lower KV motors?

I've noticed that higher voltage batteries need lower KV motors, why is this?
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15 votes
2 answers
4k 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 ...
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7 votes
3 answers
876 views

What process should I use to ensure my motors are spinning the correct direction when using Betaflight

I heard that a lot of problems occur due to one or more motors spinning the wrong direction. What process should I take to ensure that all my motors are spinning the correct direction if I'm using ...
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8 votes
2 answers
13k views

Why do brushless motors have 3 wires compared to 2 wires on a brushed motor? [closed]

I'm familiar with regular DC motors, which is what brushed motors appear to be. They have fixed stator magnets, rotor coils connected to the shaft and two brushes that power the coils at the right ...
10 votes
3 answers
5k views

How can I reverse the direction of a brushless motor?

I have a brushless motor on my RC plane. After connecting it to an ESC and testing it I've found that it is spinning in the wrong direction. How can I reverse the direction the prop is spinning?
11 votes
2 answers
664 views

What does KV mean on motors?

I've seen ratings on brushless DC motors like this one for something called KV. What does that rating mean?
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16 votes
3 answers
321 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?