Mini Quad Motor Guide

This tutorial aims to help you understand the basics of mini quad motors, which will help you choose the optimal and effective motor for your quadcopter build.

Index of Content

Looking For A Quadcopter Motor, Where to Start?

If you are new to mini quad and FPV, you should understand the relationship between motor thrust, and weight of your copter. This is useful to building any sizes multirotors.

However if you are just building a mini quad, feel free to move on to the “Motor Size” section.

Total Weight

First, of all, estimate the total weight of your quadcopter. Don’t worry if you can’t get the total weight precisely the first time, it can just be your best guess. It should include everything you plan to take on-board: frame, FC, PDB, motors, propellers, ESC’s, LiPo battery, payload (such as HD camera), and so on.

Frame Size

Second thing you need to know is the size of the frame, from which you can then understand what the propeller sizes can/should be used in your quadcopter.

Thrust Requirement

Once you’ve worked out quadcopter weight and frame size, you can now calculate roughly how much thrust the motors need to deliver in order to lift the aircraft, by using propellers of certain sizes.

Read this article about how to choose propellers for mini quad.

Thrust to Weight Ratio

A general rule is that you should AT LEAST be able to provide twice as much thrust than the weight of the quad. Remember this is the bare minimum to ensure you have a stable copter that is easy to control during hovering. If the thrust provided by the motors are too little, the copter would not respond well to your control, it might even have difficulties to take off.

For example if we had a quadcopter that weights 1kg, the total thrust generated by the motors at 100% throttle should at least be 2kg, or 500g per motor (for a quadcopter). And, of course it would be nice to have more thrust…

For faster flying like drone racing, you should expect the ratio to go much higher than this. It’s not uncommon to see someone build a mini quad that can achieve 8:1, even 10:1 thrust to weight ratio. The quad’s performance would be much more agile and dynamic, it would accelerate much faster and corner better. But when you have excessively high thrust to weight ratio, the quad would become very hard to control, because a little increase in throttle is enough to “shoot the quad in to orbit like a rocket”. :D

My recommendation is, even if you only just plan to fly a slow aerial photography platform, you should aim at somewhere between 3:1 and 4:1. Not only it gives you better control-ability, but also the room for adding extra payload in the future (like heavier cameras, or maybe extra batteries to extend flight time). But if you are into racing, then there is no limit :D Go as high as you feel comfortable with!

Motor Size

The Size of brushless motors in RC is normally indicated by a 4-digit number – AABB. “AA” is the stator width, while “BB” is the stator height or stator diameter, both in mm (millimeter). Basically, the taller stator the more power at higher RPM, while the wider stator the more torque at lower RPM.

What is brushless motor stator? – A stator is the stationary part of the motor in the middle, which is wrapped around by copper wires (windings). It’s made of many layers of thin metal plates that is laminated together with very thin insulation layer in between.

The size of propellers the motor is designed for determines the prop shaft size. Motors for 4″, 5″ and 6″ propellers have M5 motor shaft. Modern motors has the prop shaft integrated into the motor bell. Older generation motors might have separate prop adapters.

KV

“KV” means velocity constant. It’s an important parameter of brushless motors, which indicates the theoretical increase of motor RPM (rotation per minute) when voltage goes up by 1 volt without load (i.e. propeller). For example, when powering a 2300KV motors with a 3S LiPo battery (12.6V), the motor would spin at about 28980 RPM without props on (2300*12.6). Typically this just an estimation, or round-up number specified by manufacturer.

Once you mounted a propeller on the motor, the RPM decreases due to air resistance. Higher KV motors would attempt to spin the propeller faster, but lower KV motors normally generate higher torque. That’s why we tend to see larger props paired with low KV motors, and smaller props with high KV motors.

The KV value of a motor is determined by the number of copper wire winding in the motor stator, and the magnetic strength of the magnets. But generally the higher number of winds decreases the KV of the motor, while lower number of winds increases the KV of the motor.

By pairing high KV motors with excessively large propellers, the motor will attempt to spin it fast like they would do with smaller props, and therefore drawing too much current and generating too much heat. Eventually it could burn out the motor due to overheat and shorts in motor coils.

N and P Numbers

You might have seen something like “12N14P” printed on the box of a motor. The number before the letter N means the number of electromagnets in the stator, and the number before P means the number of permanent magnets in the motor.

Most motors in RC have the same 12N14P configuration. Some lower KV motors might have more electromagnets and permanent magnets to help increase torque more efficiently (and thus more expensive). While it’s good to know what this is, it’s not an essential piece of information when picking motors especially for mini quad.

Frame Size => Prop Size => Motor Size

Most of the times by knowing frame size, we can estimate what motor size we should use. This is because frame size limits props size, and each propeller size requires a different motor RPM to generate thrust efficiently.

This is where the KV of your motor comes into play. Then you’ve got to make sure that you’ve got enough torque to spin the propeller, this is where your stator size comes into play. The mathematics involved to determine the exact KV and stator size you should use is a lot more complex than most pilots care to worry about.

To make things simple, you can always check motor thrust data to verify the current draw does not exceed safety rating, when pairing the propellers you want to run.

This table below is only a simplified example to give you some ideas. It assumes you are running 4S LiPo batteries. You might also see people using slightly higher or lower KV motors than this table suggests. Frame size is referring to wheelbase (aka diagonal motor to motor distance).

Frame Size Prop Size Motor Size KV
150mm or smaller 3″ or smaller 1105 -1306 or smaller 3000KV or higher
180mm 4″ 1806 2600KV – 3000KV
210mm 5″ 2204-2208, 2306 2300KV-2600KV
250mm 6″ 2204-2208, 2306 2000KV-2300KV
350mm 7″ 2208 1600KV
450mm 8″, 9″, 10″ or larger 2212 or larger 1000KV or lower

Voltage and Current Draw

It’s important to understand that voltage has a large impact on your motor and propeller choice too. Your motor will try to spin much harder when a higher voltage is applied, and thus drawing a higher current. Always check thrust data first.

Now you have got  a good understanding of what motors you want to run and estimated current draw, you can select ESC of the required current rating.

How to Read Motor Spec

brushless_motor_1

When selecting motors, there is usually specification that comes with the motor provided by the seller or manufacturer. You should be able to find information about the power, thrust, rpm etc. This is an example of the 18-11 2000kv Micro Brushless Outrunner (10g).

quadcopter motor data-sheet

quadcopter motor spec

Basic Mini Quad Motor Performance Factors

Once you have decided on motor size, you might already have a handful of motors to choose from. To pick the best motor for your application, you should consider the following factors:

  • Max Thrust
  • Current Draw
  • Efficiency
  • Weight

The decision here really depends on your preference, how you want your aircraft to perform.

Thrust and Power

Thrust is probably the first thing people look at when choosing a motor.

Higher thrust gives you faster acceleration, but you also need to look at efficiency, making sure it’s not using a ridiculous amount of power that exceeds what your hardware can support. Don’t abuse your batteries with amperage-hungry motor/prop combo. If your quad could draw a large amount of current at high throttle, your battery’s max discharge rate has to be able to keep up in order to provide the power, as well as they don’t overheat and go buff (check out C rating).

However I don’t believe motor power and thrust are the only things that represent the whole picture of motor performance.

Motor Weight

One thing that often get overlooked is motor weight. It’s a very important factor for racing drones.

Since the motors are mounted at the corners of the frame, they have an obvious influence on the responsiveness of your quad. Heavier motors increases the moment of inertia of your quad, making it harder to change angular velocity. In practice, when your quad is doing flips and rolls for example, it would take some time to pick up that angular acceleration and eventually move to the desired position. Heavier motor requires more torque

The motor itself also has moment of inertia since it works by spinning. The heavier the motor is, the more torque it requires to spin, and therefore takes longer to change RPM. And again that affects the responsiveness of the motor and the quad as a whole, the quad would feel less precise and more work for the PID controller.

The weight of a motor matters a lot more for those who do acrobatics and racing.

Power Efficiency

Motor efficiency are typically measured in gram/watt (thrust/power). It’s important to look at efficiency through the whole throttle range, not just the top end. Some motors might be efficient at lower throttle range, they could lose efficiency by drawing increasingly higher current as they approach their limits.

With less efficient motors not only are you wasting a lot of energy and flight time, your batteries might also suffer from voltage sags. Inefficient motors either generates too little thrust or draws too much current, so another good way to look at it is to use gram/amp (thrust/current).

Advance Quadcopter Motor Performance Factors

Many motor properties are not mentioned by the manufacturers and can only be found through user testing.

  • Torque
  • Response Time
  • Temperature
  • Vibration and balance

Torque determines how fast a motor can change/increase RPM. It affects how precise and responsive your quad feels in the air. A motor with high torque gives more snappy response, because of the faster change of RPM. You might even see less prop wash. High torque also means you are allowed to run heavier props in the cost of sucking more current. However if you put that heavy prop on a low torque motor, it simply won’t have the torque to spin it (can’t achieve the desired RPM) and results in lower thrust and lower current draw. However one drawback of high torque motor is oscillation that is hard to tune out. Because the high torque motors react so fast and able to change RPM so rapidly, it might amplify the error and cause oscillation especially in yaw axis.

Response Time – this is a product of torque, high torque usually means fast response time. One easy way to measure response time is to see how long it takes for a motor to go from 0 RPM to full RPM. And obviously, response time is going to be different from prop to prop

Temperature – magnets in our motors get demagnetized faster in high temperature, and performance of the motor decreases. Therefore a cooler motor means longer motor life

Vibration – If a motor has poor balance or build quality, you might experience vibration that affects your quad, making PID tuning much harder. Some people tried soft mounting motors, or/and the flight controller to reduce vibration and achieved some really positive results. Bashed and unbalanced propellers could also cause vibrations on the motor.

Features in Mini Quad Motors

There are so many variables that affect the performance of a motor, it can get complicated very quickly. For example for motors that are the same stator size and KV, you might get very different thrust and current draw running the same props, because of the differences in design and hardware. (different magnets or air gaps and so on)

The following features contributes to better performance in some aspects of the motors, and might also change motor characteristics.

Hollow shaft

it allows stronger/heavier metal for more robust shafts yet the weight remains the same (or even results in a  lighter motor).

Type of Magnets

Magnets such as N52, N54 etc, are a grade of the magnet according to their magnetic field strength; the higher number, the stronger they are; stronger magnets gives higher torque and faster motor response.

Stator lamination thickness

in a nutshell, the thinner, the better as it increaes the power, reduces the heat generated as leads to better efficiency.

Smaller air gap

how far the magnets are from the stator, the closer the more energy efficient and powerful, also it improves torque and response.

Wire gauge in winding

larger wire gauge allows larger current without burning up, but it would also be heavier.

Arc Magnets

Arc magnets (aka curved magnets), is a technique to bring the magnets closer to the stator; allows more consistant and smaller air gap.

C-Clip / E-Clip / Screw Shaft

To hold the motor bell to the base, motor manufacturers use one of these methods on the bottom of the motor to lock the shaft in place: C-clip, E-clip or a screw. Each of these ways has their pros and cons, and it’s hard to say which one is the best.

Generally speaking, screws are better for user maintenance as it’s easier to remove a screw than a C-clip or E-clip. But screws suffer from risk of over-tightening and locking the shaft (making the motor harder to spin).

You might hear stories about C-clips popping off during flight, which causes the motor bell to fly off and crash. However, screws are not immune to this problem.

Other Features

  • Soldering tabs on motor
  • ESC integration
  • Cooling design

All these features make modern motors more powerful and robust, yet draws a lot more current too! There are some negative impacts from smaller air gap and stronger magnet. Because of the stronger magnetic field, you might not be able to run high voltage such as 5S or 6S without risking burning your gear, because they simply draw so much amps! You might also notice a high current draw with heavier props, putting a lot of stress on LiPo batteries and ESC’s.

CW and CCW Motors

You will sometimes see motors labelled as CW and CCW. They stand for “Clockwise” and “Counter Clockwise”.

However this does not mean they can only spin one direction. They are essentially the same motor that can spin both directions. The only difference of CW and CCW motor is the the direction that the prop shaft is threaded.

The intention is to use 2 CW motors and 2 CCW motors on a quad, so that when the motors spin, all four prop nuts get tightened rather than loosened.

To tell if you have the correct threaded motor on, simply hold the prop nut on the shaft, then start turning the motor with your hand in the direction it should spin. If the nut tightens then you got the correct one :)

However I personally prefer to get all motors of the same threads so I don’t confuse myself with the different prop nuts.

Balancing Motor

After you received your motors, the first thing you should do is to balance it. Although it’s not always necessary, it’s a good practice. I personally only do this on large motors though like 2212 or bigger. For mini quad motors I normally find balancing not necessary because the build quality are generally very good. (2208 or smaller)

Mini Quad Motor Recommendation

There are so many options out there, it will give you an headache :D in this mini quad parts list I searched for all the popular motor options for mini quad.

Here is a list of top 5 motors from the community.

Article was created in Oct 2013, Last updated in Nov 2016.

132 thoughts on “Mini Quad Motor Guide

  1. Joshua Miller

    Hello Mr. Liang
    Thank you so much for everything you teach us through your articles, few people are willing in teach us in this interesting way that you apply.
    I have a quad whose stock engines are brushless 2212 1150Kv, few days ago, I ordered two engines of the same reference for have extra engines but they sent me reference 2212 950Kv.
    Then, can I mix 950Kv engines with 1150Kv engines?
    Another thing: the new engines are X2212.
    Does that ‘X’ have some relevance? I don’t know what is the difference between 2212 and X2212…

    Many Thanks again.

    Thanks.

    Reply
    1. Oscar Post author

      maybe, but the motors will output different power at the same throttle level.
      the flight controller might be able to handle it and make it fly… but it will oscillate and flies poorly, so try to avoid it.
      The letter X is probably just a model set by manufacturer, it doesn’t mean anything to me.

      Reply
  2. Harish Patel

    Hello,
    I have a payload of 1 Kg. So, according to my knowledge, the weight of the quad should be 2 Kg. So, the total MTOW will be 3 Kg. Now, in this case, what should be the thrust produced by the motors? 6Kg or 3Kg?
    I want to fly it with and without payload.
    Please suggest me.

    Reply
    1. FlyNfool

      Depends on how much flying you plan to do with the payload vs without.

      At 4K thrust it will fly, but be sluggish with the payload. Without payload it will fly great.

      At 5K thrust it will carry the payload well, and be pretty peppy, slightly overpowered with out load.

      At 6k thrust it should fly very well with the payload, like it was designed to be that heavy. With out payload it will be very overpowered.

      These are my best estimates. Too many factors to tell you an exact number.

      Reply
  3. Matthew Alexander Thomas

    I’m being 100% serious when I ask this.
    I’m working on mobile air structures, I’ve already figured gargantuan sized batteries and have figured my total weight to be around 8,000-10,000 lbs.
    Does anyone have any kind of idea the propellar size, and engine size I would need for this kind of weight?

    Please and thank you in advance.

    Reply
  4. Larry

    So, I live at 7500 feet. I often fly at 8000 – 10000. Other times I fly 2000 – 5000 feet.

    Would it be of much benefit to have props with more pitch when I fly up at 10000 feet?

    Reply
  5. chinthana

    Hi oscar.

    I wont to make a powerfull multicopter like a vole copter and i wont to fly ..with 8 moters. What item now I buy for my project.
    Please help me..

    Reply
  6. shailesh

    hello oscar…
    i want to make a quad copter for teck fest can u give me a specification for full parts of quad copter
    it should fit in a circle of diameter of 50 cm and we should have full control on our quad copter

    Reply
    1. dhruvraj

      I want to make a drone wich have power full motor & range of max. Distance & with 4 axial glimbal & fastest speed+ max. Tlite angle go to home + pause at same position please give me a list of requir tings for this

      Reply
  7. Goeters

    Need some advice
    i have 2830 900kv ntm motors with 3 blade 1045 props,with gimbal and gopro and 4200mah 20c lipo and 25a 4in1 qbrain esc
    total weight of the cuadopter is about 1,8KGs …the copter has allot power but the motors gets very hot due to the weight and props etc, are there any other size props or other motor configuration i can use so that the i dont have this heat problem on the motors, my max flight time is about 9mins
    i think better stronger motors is maybe the a better solution but what motors then ?

    any suggestions ?

    Reply
  8. Snuffy

    Aloha Oscar,

    BLUF: Prop will not properly fit motor shaft.

    I am having difficulty locating the correct PROP or PROP Adapter. I have these motors:
    — LHI 4x 2212 920KV (amazon.com/LHI-920KV-Brushless-SIMONK-Phantom/dp/B00XQYTZQ2?ie=UTF8&ref_=pe_527950_33920290)
    and these 10×4.5 blades (amazon.com/gp/product/B00KMJV50I/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1)

    The blades come with inserts but the motor shaft is keyed (has two flat spots).

    The motor shaft is 7.7mm in diameter and 6.75mm where it is keyed (notched) on each side. The length of the shaft is roughly 14mm but 7mm of that is threaded at a ~ 5.8mm.

    This is on a cat 450 frame. Request to know what 10″ props are already keyed or which prop adapter one should purchase. I do not think I need a adapter since two prop nuts are CC threaded and the other two are CCW threaded.

    Thank you for your valuable time and any assistance you can provide.

    All the Best,
    Snuffy

    Reply
    1. alex

      HI, interesting read.
      If i require a hexacopter or a quadrocopter to lift 12-15kg payload with a flight time of 30 min and range of 3km – 6km what configuration from frame to the entire kit would you recommend?
      Thanks.

      Reply
  9. Hemantha

    I am a newer for RC Tech. I am trying to make RC electric Airplane. I have a A2212/5T 2700Kv motor, 30A ESC, 11.1V 25C Lipo, 6×4 E propeller, Transmitter and receiver. Are they suited for each other? How much weight can be thrust?
    what is the recommend values?
    what is the suitable propeller for A2212/15T 930Kv motor?

    I want to know , Can I use Multi copter propeller for Airplane(correct rotating side )? ‘GWS 10×47 ‘ propeller for Multi copter or Airplane , all are same?
    anyone can help me?

    Reply
  10. Ankur Rana

    hey oscar i m in serious problem …..
    me n my friends trying to build a drone, we do everything as u said above but when we increases the speed of our motors it suddenly disarm ….so we cannot take off due to this disarm problem can u plzzzz tell us what are we missing now…..

    thank u,

    Reply
  11. ritik

    hello,
    i have the motor for my quadcopter with following specification:-
    A2212 1000KV
    – RPM/V :1000
    – Stator Diameter(mm) :22
    – Stator length(mm) : 13
    – Stator Arms(mm) : 12
    – Magnet Poles : 14
    – Motor Winding : 22
    – RPM(KV) : 1000
    – Idle Current(A) : 0.55/8
    – Max Current (A) : 17
    – Max Power(W) : 190/3
    – Rotor Dia(mm) : 28
    – Shaft Dia(mm) : 3.17
    – Motor Length(mm) : 28
    – Overall Length(mm) : 42
    – Biggest Thrust g/S : 1200/4

    i want to know how much mah & max. /min. discharge rate battery would be required for the motor

    Reply
  12. Hexacopter

    Hi Oscar,

    I am designing a hexacopter and I need motors that have 50% thrust of 850g. Could you suggest any name of motors that are available to buy online?

    Thank you so much and I really appreciate it.

    Reply
  13. Avishek Sengupta

    Hi Oscar,
    I am using 1000kV motors for my quad. I am aware the lesser the kv rating is higher is the altitude that the quad can climb upto. Now how do you work out the exact altitude in ft/m that it can fly upto using the specs of the motor and other available data. Also how do you calculate the flight time. Is there a particular formula you use? Thanks!

    Reply
  14. Vivek gr

    hey oscar.Can you suggest me am a bit of confused. My HMF Hexacopter 550mm AUW is 2500gm. What motors and props can I use so that I get enough power at around 75% throttle??

    Reply
    1. Oscar Post author

      so you want motors that can generate 1KG of thrust each, so you are looking at 2212 size motors that supports 9 or 10 inch props should be sufficient.

      Reply
      1. Dominic

        Hi Oscar, it seems like not having data for power systems is very common, which is unfortunate. I am from RCbenchmark and we developed this test stand that really helps with ensuring you have the correct setup for your creation. With this you can measure and record to your computer thrust, torque, efficiency, rpm, all in the same device. It sure beats having to time your flights to test every possible combination!

      2. Matt Wallwork

        Hi Oscar/ Vivek,
        I’ve found with 2kg + on a 450 quadcopter, the 2212s are working hard with standard 9545 props or 1045s. I switched to 4006 (3508 would do) 680kv on 3s and 1155 props, it handles the extra weight much better. With these motors for 2.2- 2.5kg I could go to 4s batteries on 11″ props, or 1255 props on 3s with no problems. I’d get bigger than 2212 motors for a 2.5kg quad. Normally, you want a 3:1 thrust: weight ratio.
        Hope this helps!

  15. sanjay kroliya

    Hi oscar, i tried to built my quadcopter with 12*4.5propellers please tell me about motor . which motor is better for my quadcopter..

    Reply
  16. Jose

    I am currently doing a drone and it is my first time. I followed some videos and they chose to use 1400KV motor and 8*4.5 propeller. I just want to know what consideration they took to decide to use that combination. Can anyone please explain to me please? It will benefit me greatly.

    Reply
    1. Oscar Post author

      Hi Jose, maybe you should ask them ? LOL
      when choosing props/motor, you need to consider the frame size, thrust they generate, and power consumption.
      If you already have some ideas of other prop/motor combo you want to run, compare the data with this setup, and choose one that fits your need better.

      Reply
  17. E.L.K.

    Hi Oscar!

    I’m now deep in investigating about building my own 250 fpv quad and I performed a serie of researches on how to find out better combination of battery+motor+prop depending on the weight of rest flying part.

    Sooo…. the main approaches I found is: “approximate by these (random formulas for props) formulas” – this approach gives very rough approximation, “buy and probe” and “look at other’s measurements and approximate”.

    Also there are a bunch of calculators in the internet, but these calculators does not allow to add own elements.

    You are the one, from who I saw the words “try to model it” and thus I’m writing to you to ask for your opinion. I also wrote in the G+ , but I assume that you not reading that post.

    I combined approaches “look at other’s measurements” (actually, I took yours ((: ) and “modelling”. And this lead me to having a bunch of haskell code, which allows me to “guess” parameters for simple mathematical model of prop and motor basing on the test data provided to the system.

    I’m estimating thrust and power absorbtion of prop by simple exponential, like ones found in http://www.flybrushless.com.

    And motor is estimated by motor power formula from here http://www.rcgroups.com/forums/showthread.php?t=337735 which is:

    Power Out = (V – Iin * Rm) * (In – Io)

    basing on these formulas, this system solves the equation

    propeller absorbed power = motor power out

    for current, which allows to calculate all other params (rpm and so thrust).

    Long story short, to see if this approach provides any reasonable results, I tried this:

    1. From known kv of cobra motor and test data from here https://oscarliang.com/best-prop-cobra-2204-motor/ I made the system to guess coefficients for cobra motor and gemfan_5030 props.

    2. From guessed gemfan_5030 props and test data from here https://oscarliang.com/emax-mt2204-mt1806-motor-quadcopter-1804/ I made the system to guess coefficients for emax1806 motor.

    3. From guessed emax1806 motor and test data from here https://oscarliang.com/motor-180-mini-quad-4-inch-prop/ I made the system to guess coefficients for the gemfan 4045 props.

    4. I made the system to calculate performance of guessed in last step gemfan 4045 motor with the guessed in first step cobra motor.

    At the step 4 I got next results:

    12v: thrust 234g, current 4.54 A
    16v: thrust 329g, current 5.7 A

    while expected, according to your measurements are:

    12v: thrust 270g, current 4.9 A
    16v: thrust 351g, current 6.7 A

    so predicted parameters are 15% close to the ones got from tests, after 3 steps of guesing parameters, with only small amount of test data.

    Looks pretty promising from my point of view. And I’m pretty sure that if I’d have more data points for guessing coefficients, the results will be much more accurate and thrustworty.

    The ideal situation I dream about is when people will be able to provide the models of the motor and props they tested instead of plain test data, so any modelled prop can be virtually tried with any modelled motor to find out ideal combination for every exact case (like most trust or longest hover).

    Can you, please, share your opinion on this approach? Maybe it is something I don’t know about which makes all this meaningless? Are you interested in participating in developing of such modelling system?

    Reply
  18. arif hassan

    Hi Oscar
    i need your help to choose right propeller for my 450 quadcopter. i have not test my quad yet because i cannot choose right size of propeller for my quad
    here are my components
    2212/13 t 1000kv brushless motor
    30amp esc
    Q450 frame
    3s lipo 3000mah 30c constant
    and the total weight of my quadcopter is 850-900 grams i am not doing any fpv like thing so please help me to decide right size of propeller Thank you
    please reply

    Reply
  19. Sebastian

    Hey,

    I have been reading a lot here!!! Really great info all around!

    I am about to build my own first 250mm quad, and I am still a bit unsure about the motor prop combination.
    Was thinking about going Cobra 2204 1960KV with Gemfan 5030, the same setup as you used in your ZMR250 Mini H Quad Build.
    But since the Cobra 2204 1960kv are hard to get I was looking around and found the DYS BE1806 2300kv. The data on the Rotorgeeks website looks nice! rotorgeeks.com/index.php?route=product/product&product_id=152
    I would like to use 4S, and I am thinking to get these ESCs readytoflyquads.com/spider-lite-18a-esc-blheli-oneshot) even if they are a bit too overpowered.

    The rest if highly comparable to your ZMR250 Mini H Quad Build:
    ZMR 250, Flip32+ (Cleanflight), Taranis, MinimOSD and maybe a PDB for the ZMR250

    Any ideas and thoughts about the motor/prop combination from you would be awesome!

    Thanks for all your help so far (from reading your website)

    Reply
  20. Vishwanath

    Hi Oscar,
    i need a small help regarding selecting the right propeller size and motor KV (brushless) ?
    In order to fly my quadcopter i need a thrust of each motor 600 GRAMS i.e my total weight of quadcopter is 2500 GRAMS .
    SO KINDLY GIVE ME DETAILS BELOW !!!
    MOTOR -_______(KV)
    PROPELLER- _____(DIAMETER):____(PITCH)

    THANKS !!! in advance

    Reply
  21. Poply

    Hi Oscar.
    My question may sound awkward.
    So, can you tell me the specification of a BLDC (for quad) if the weight we wanna lift is 60kg? It’s not impossible right? Please do reply.
    Thanks.

    Reply
  22. Noah Alley

    I was looking at doing a a x8 rotter design for a senior project any suggestion on what type of battery and moters i should use

    Reply
  23. marcel

    hi there
    your blog is great thank you for this..
    my name is Marcel im from czech republic….
    so my question is how i can improve longer time in air….
    i have this quadcopter… ebay.co.uk/itm/X525-V3-4axis-QuadCopter-Glass-Fiber-Folding-Kit-w-KK2-15-KK-MK-T6-2-4ghz-TX-RX-/331514381283?pt=LH_DefaultDomain_3&hash=item4d2fcc03e3
    total weight is between 650g to 700g without battery..plus gopro and gimbal….im not sure what battery is best for use ….3s battery but how many Mah for best economy…
    also if i can improve propeller or motors for longest time in air….
    im sorry for this questions but im new…)))))
    best regards

    Reply
    1. Oscar Post author

      it’s difficult to say without actually test it, every quad setup is different.
      I think for your setup, 3S 2600mah would be a good one.
      But to identify the best capacity VS flight time, check out this post.

      Reply
  24. Amit

    I am working on a project that has a bot of about 40kgs. Can you suggest motors and prop sizes suitable to lift the bot up?

    Reply
  25. Kumar Shubham

    Hi Oscar! While I found this article very interesting and useful (thanks for that), yet there are a few doubts of mine which I believe you will be able to sort out.
    I am making a quadcopter for aerial photography, so I have excessive weight in my system. Consequently, I will need more thrust and hence propellers with shorter pitch should be what I am looking for. However, shorter pitch will mean that my drone will take more number of revolutions (and ultimately power) to lift up by the same distance as a drone with propellers having higher pitch would. What should be my approach then- high pull-up capacity with slower pull-up, or low pull-up capacity with(if it works) faster pull-up? Please suggest some dimensions.

    Reply
  26. jedichen121

    Hi bro,

    I’ve been wondering where did you get the spec of the motor you showed as example. I couldn’t find data like suggested prop, or thrust on the hobbyking website link you posted. Thank you very much.

    Reply
  27. Mufaddal

    hello bro…
    i want to get thrust of 7.5 kg..means i want to lift 15 kg of weight…i cannot understand which type of motors & which types rotor blade, i can use..i also want flight time around 25 minutes..so there is an issue about power..for this specification i have to design he whole thing from the start.. i know this is difficult but if you could give me a hint,it will be very nice of you..

    Reply
    1. Oscar Post author

      first, find out what thrust you are after, then decide on prop size.
      this you will find how much current you will expect and you what ESC you should use.
      but looks like this motor is rated at 16 max current anyway, i think 20A ESC would do (for props smaller than 16 inch)

      Reply
  28. Pratik

    HI Bro,
    i am using these parts. please tell me which parts should i use

    Avionic PRO C2822 KV1400 brushless motor 41g(from rcbazaar.com)
    OR
    DYS BE1806-13 Brushless Motor for Multirotor (2300KV) 24g(from hobbysea.com)

    5030 Carbon Fiber Propellers CW and CCW Rotation (1pair)(from hobbysea.com)

    please suggest me a esc for the motors

    Reply
  29. raj

    i have doubt about the orientation of motor. Some motors like ‘EMAX Motor MT2213’ have the proper orientation clock wise or anti clock wise but other don’t.How to choose motors in that case??

    Reply
    1. Oscar Post author

      Note that EMAX motors come in Clockwise and Counter Clockwise threads for securing the props to the motors, to avoid loosing props mid-flight… you need two CW and two CCW ..

      Reply
      1. raj

        thanks, while choosing the propellers , is it necessary to follow the recommended suggestion given on the motor. I have calculated my own thrust using static thrust calculator which is totally different from the suggested one.

        Prop: 10×4.5 with 3S Lipo (11.1V)
        8×4.5 with 4S Lipo (14.8V)
        Max Thrust: 850gms with 3S or 750gms with 4S
        ESC: 20A
        KV: 935/V Wt: 55Gms

      2. Oscar Post author

        It’s not necessary, but it’s safer. Try and see if you can find any thrust tests online, done by third parties. Compare the data and find the best size prop.
        Or if you are still not sure, doing your own thrust test it’s not difficult.

  30. James G. Peter

    Hi, i want to know the real price of Hexacopter Motors with different manufactres, i hope i would see my reply through my email. And i haved prepared everything such as frame, Camera, and Controller but Motors and ESC we don’t have it in our area. i hope you guys you can help me where to get six (6) Motors and six (6) ESC for my new project “Hexacopter”.

    Do you guys export it if i buy it from your company? am in Nigeria – Leaving in Borno State. how many days will take you to bring it back wen i purchase it.

    Reply
  31. Shivam

    Hey nice article above.
    I am a first year college student.My friends and I are planning to make a very basic quadcopter. We are having problems regarding specifications of motor and battery. It would be very nice if you could help us out. Our quadcopter should be around 1100 grams(1.1kg). We are planning to use wood for frame. It would be very helpful if you could tell what kind of motor should we use and how powerful battery should be sufficient. We plan to use 4 motors and 1 battery only.

    Reply
  32. Vignesh

    Hello bro,
    I am making a quadcopter using the following parts
    1)hextronik nanowii V01 from HK site
    2)multistar motor type 2213 935KV
    3)10*45 propeller
    4)3 cell 3000mAh tunigy battery
    5)turnigy plush 30Amps*2 for two motors and 25Amps*2 for the other motors
    6)Flysky controller model FS-CT6B.

    So far I have fully assembled my quad all the motor direction and all connections are correct.I used multiwii to program my nanowii controller,so i have set as #define MINTHROTTLE 1150 and #define MAXTHROTTLE 2000 also i calibrated my ESC initially using the #define ESC_CALIB_CANNOT_FLY command in the config.h of the multiwii.ino,but I am facing a problem.
    After I arm the motors and star to raise my throttler one of my motors(rear-right) is staying constant at 1150 for a while while the other three motors raise up.After sometime the fourth motor(rear-right) also increase and at full throttle three motors are running at 1960rpm while the fourth motor(rear right motor) runs at 1660rpm(as seen from the multiwii GUI). Even during the flight it has terrible problems during take off in fact it is not taking off since three motors are at a higher throttle it tumbles over rapidly. Please Help..

    Reply
    1. Oscar Post author

      Hi Bro, First of all, why are you running 2 different types of ESCs?
      you need four identical ESCs, Then calibrate your ESCs and try again.
      thanks
      Oscar

      Reply
  33. puja

    hi oscar, i’ve a doubt. how much weight of propellers are used in helicopters? is each copter can have different speifications r same?

    Reply
    1. Oscar Post author

      propellers are usually a few grams, of course that depends on the prop size. Usually the weight of the prop can be ignored, size, pitch and material are what matter.

      Reply
  34. Mike

    Hi Oscar, love your website! New to the scene and looking into building my first EMAX 250 Carbon Fiber FPV. I do not know the pros and cons of motor size between these two. EMAX MT 2204 2300KV or the EMAX MT 1806 2280 kv. After reading this article I assume the 2204 size will draw more power and less fly time. Besides that fact, what kind of characteristics between these two motors will be different?

    Reply
  35. Nothing

    Hi,
    My model weight specification is:
    – Model weight : 800gram
    – 1400KV motors from Mystery
    – 40A Skywalker ESCs with BLHeli firmware.
    But when I use 8*4.5 propeller, it can’t take off. So, I decide to use 10*4.5 propeller and each motor provides about 600g of thrust. But after small time of running, motors are hot. I wonder if it’s ok or not?
    P/s: the battery is ok, not hot at all.

    Reply
    1. Oscar Post author

      10 inch prop might be too large for these motors. the recommended prop is 9inch for 3S lipo. What’s the max thrust you can produce with these motor?

      Reply
  36. Vignesh

    I have got a doubt . I feel like most of the thrust generated by the propellers are being wasted since they are open, So my question is that if it we use some conical enclosure under each motor and propeller assembly and thereby channelizing the power(thrust) or the flow of air, can we achieve greater flight time and greater stability since the interference of the air flow between the motors is reduced? Am I right or wrong?

    Reply
    1. Oscar Post author

      I think that’s an interesting idea I have not thought about. I am sure I have seen it somewhere, but that’s not a common setup, probably for a reason.
      Somehow I am concerned about the outward air flow within the conical enclosure will bounce off the wall, and interfere the main flow of air even more.
      I can see this theory needs a lot of experiments to verify, and can get extremely academic and deep… :D

      Reply
      1. Lynn Sim

        Ducted fans, propellers with a short cylindrical tube around each propeller should increase the directionality of the airflow, thus reducing any turbulence caused from mixing with the air form the other propellers, thereby maybe increasing the thrust. However, I’m not sure that the extra weight added by the cylinders would offset the slight gain in thrust. As you noted, good material for experimentation.

    2. oliver

      no.
      you add weight which is way more than gained FT.
      plus, you have optimized it for hover, as soon as you start flying in any horizontal direction, airflow changes from vertical to (mainly) horizontal

      Reply
  37. Radboud

    If i want bigger payload such like a camera on micro Brussless motors. Should i use larger props? Stock is 14cm. I use 15cm witch is better performens and stability. I am wondering of i could use 21 cm props. Would iT give me more stability?

    Reply
    1. Oscar Post author

      it doesn’t work like that. It depends on how much torque your motor can generate. larger props requires more torque, if your motor cannot deliver it, it will just draw more current and produce less lift, it might burn your motor and ESC.
      You should be able to find out what is the maximum size prop you can use from your motor data sheet.
      Generally smaller props give better stability, because the faster change of RPM.

      Reply
  38. Alun

    Hi, I am building a 450 alien X quadcopter total weight so far is 1000g.. 25amps q brain 4 in 1 speed controller,no fpv equipment yet but will be adding once i learn to fly….Anyway I have mistakingly ordered sunnysky x2212 1400kv motors… thinking they were the 980 kv ones..!!!!. So have the wrong motors, these took 6 weeks to turn up so dont want to send them back and wait another 6 weeks… the quad is almost ready to fly… i have some graphs of the motor specs if you need them.. any suggestions as to what prop size to run… for an easy quad to operate while i learn i dont want speed just longish flight times, currently have 2 2200mah batteries… please advise….

    thanks Al…..

    Reply
  39. kaluya moses

    Thanks a lot Oscar for the generous heart to all drone /flight hobbyist like myself now I think now I have got the way to my vision. Though i come from third world country ( uganda) but think you will able to guide me where possible please!
    best regards moses kaluya.

    Reply
    1. Oscar Post author

      You are welcome Kaluya! it doesn’t matter where we are from, we all love this hobby and we are all having the same fun doing it :D

      Reply
  40. Ariel

    Hi there,

    Love your blog, it’s no. 1 regarding to getting info and news about multicopters.
    I have a question concerning the meaning of the motor no. let’s say that here you talk about the 18-11 2000kv Micro Brushless Outrunner (10g) So what would the 1811 mean and I already understand that the 2000 in this case is the rpm.
    Another example to my question: I saw this multistar 2206-2150kv on HK, again what the 2206 mean?

    Thank you (-:

    Reply
    1. Oscar Post author

      Hi!
      1811 is basically the indicator of the motor size.
      first two digit is the diameter (width) of the motor bell, last two digit is the height of the motor.
      so for example, 2204, is a “fatter”, wider motor, but shorter than 1811.

      It indirectly implies, the power of the motor: the fatter and taller the motor is, usually it’s more powerful and heavier too. Also the motor mount screw holes might be different according to the size. But this is not always the case, check datasheet before buying.

      thanks
      Oscar

      Reply
  41. sunny

    buddy i want to add a bit of transformers stuff , quadcopter automated to transformer in to all wheel drive car (4 wheels power by 4 motors) but i have no knowledge on electronics it’s not my cup of tea .could you suggest type of micro processor i should look,so that it can work as both automated /semi automated quadcopter and car .it also perform transformation from quadcopter to car then car to quadcopter

    Reply
    1. Oscar Post author

      wow, that is going to be a huge project if you are doing it alone!
      I would say an Arduino Mega, or two Arduino nano would be ideal.
      There is already open source multicopter project on the Arduino, all you need to do is write the code for the car, and put it together!

      Reply
  42. Vishal

    I got confused at your equation for required thrust. Maybe you should write it as

    Required Thrust Per Motor, to avoid come confusion.

    otherwise great article!

    Reply
  43. deepanshu tiwari

    Sir please tell me what is the airfoil section which is used here in the propeller.I want to know how the cord and camber length varies along the radius.which section airfoil we must choose.

    Reply
  44. Aman Gupta

    Dear Oscar,

    I’m Aman Gupta, class X from Kota (Rajasthan).

    I just want to know some best online stores for motors. I’m making it for the first time so I want it second hand. Can I get it within 150 to 300 rs?

    With best regards,
    Aman Gupta

    Reply
    1. Vignesh

      Lol you cannot get any motors for 150 to 300 rs. And I don’t know if you can get the motors in second hand. And also I wont recommend it. Just Buy from Hobbyking brand new and you are good to go.

      Reply
  45. Tomas Preece

    Oscar,

    Was nice and useful to find your blog! thumbs up for that!!!.

    My question is the next one:

    i recently buyed a tarot 650 Carbon fiber quadcopter with 3d gimbal

    and i bought this motors:

    NTM Prop Drive Series 35-48A 1100kv / 640w

    hobbyking.com/hobbyking/store/__16232__NTM_Prop_Drive_Series_35_48A_1100kv_640w.html?strSearch=ntm%201100kv

    i need to know if they are enough to lift an estimated 4kg. of payload (or if im dreaming).

    i will use this propellers:

    Carbon Fiber Propellers 13X4

    hobbyking.com/hobbyking/store/__25694__Carbon_Fiber_Propellers_13X4_LH_and_RH_Rotation_Pair.html?strSearch=13×4%20carbon

    and this ESC:

    Hobbyking 70amp OPTO ESC with 5 Amp External UBEC

    hobbyking.com/hobbyking/store/__28225__Hobbyking_70amp_OPTO_ESC_with_5_Amp_External_UBEC.html?strSearch=70%20opto

    also which setup of batteries (4S) do you recomend for a flight time near 20 minutes or more? one big battery or 2 in parallel? which size of propellers do you reccomend for that setup to maximize my flight time??

    Thanks a lot for your time it is very appreciated.

    Please if you can write me back at my email it would be awesome! so i can reply right away!

    Reply
  46. vava

    i want to make a hexacopter which could carry 4 kg weight can u help me in choosing the correct motor-propeller combination? :(

    Reply
  47. 3Dprintedvtail500mm

    hello guy newbie here who 3Dprinted his own vTail quad and outfitted with 1100kv turnigy motors and 11*5 props on a 4s LiPo 3k MAh with a kk2.1.5 board all setup and all but i have a few Q’z b4 i blast off…

    ok i wud like to hear
    pros vs cons as far as my setup ?
    chud i change props?
    will i be able to fly high (clouds)?
    will it be fast or slow?

    i guess this are my main questions , i rather ask before i fly and crash lol

    Reply
  48. 3DprintedVtaill500

    hi guys i have a newbie question , im running a vtail 500mm 3D printed at home and im putting turnigy 1100kv motor with 11*5 props and a 4s 3k mah and a kk2.1.5 board ……

    any confidence in taking off?
    should i change props?
    will this setup get me high?
    what might be the pros vs con that i might exp?

    im like in my final stage but dont want to risk it so rather ask first

    Reply
  49. Tristan Semmelhack

    Thank you very much!! I will look into better motors and/or reducing weight.

    P.S- I am also being supervised by a parent! Thanks for your concern though.

    Reply
  50. Tristan Semmelhack

    Hi!

    I am a 12 year old and have built a small 330 size quad. I am slightly worried about my motors not being powerful enough for the quad. My quad specs are 1.1kg, D2822 Turigy Aerodrive 1100kv Motors (which have a thrust amount of 540g per motor) and a 2200mah, 3s 40c lipo battery. Am I straining my motors? Oddly, the battery, ESCs and motors are barely warm at all after flight. I also carry a gopro and the motors and other parts are fine. I look a the dji phantom which is much lighter and it has 935kv motors… Am I missing something? The quadcopter is also still quite maneuverable has normal flight characteristics as my others. Just want to make sure I don’t damage my quad!

    P.S. I am running 8*4.5in props for lifting more!

    Thanks!

    Reply
    1. Tristan Semmelhack

      Update: the weight is actually 1.2 kg and the motors are also quite warm now after flight and with a go pro, I take off at 1/2 throttle (a bit more in fact). Without a go pro, I take off at less than 1/2 throttle.

      Reply
      1. Oscar Post author

        Hi Tristan,

        it’s great to see young minds like you picking up this hobby. But I am concerned about your safety since you are only 12! Are you being supervised by an adult when doing this project?
        Quadcopter is not a toy, it can be very dangerous!

        what you have is flyable. But I would use stronger motors, because 330 size quad should be very agile being able to do arobatics, you probably want to have 1:3 weight to thrust ratio, that means having 3KG of thrust in total, 750g thrust per motor would have been better.

        But I think 1.2KG for a 330 size quad, is a bit heavy. I think normally that size should be around 800 to 900 grams (including gopro).
        try to reduce the weight down, and use your current motor should be fine.

  51. Muhammad Ahmad

    Dear,
    I want to make an airplane of weighted about 1.5 kg including all access.
    An esc of 30 amp . A battery of max 2200 mah . 9g micro servo. So which motor you would refer me.
    In runner or out runner , of which rpm and efficency and thrust and propeller size.
    Tell me about that model which is easily available in pakistan and best for me.
    Thankful to you.

    Reply
  52. Fonse

    Hello, I have a beginner’s question.
    Generally speaking which type of motor will draw more power,
    The Low Kv or the High Kv motor?

    I’m building a quad and I want to get a few more minutes of flying time and I don’t know if I should use a 1000 kv motor or something around 700kv, I know I’ll be using different size propr obviously but which motor requires more power to spin?

    Reply
    1. Oscar Post author

      Hi, If it’s the same model motor, the higher KV motor will draw more current with the same voltage and prop. For example, the Cobra 2204 2300KV will draw more current (higher power) than the Cobra 2204 1960KV at 3S battery.

      Reply
  53. Afshin

    Hi,
    I want to make a quad for lifting about 1 kg.and so i required parameter of motor , propeller size and battery required on it.(min flight time is 10 min).
    Thank you very much.

    Reply
  54. Imi

    Hi,

    Usually I order from hobbyking, but I can’t find at the thrust data in the data sheet of the motors.
    How can I calculate the thrust of the motors? If it possible of course.
    What would you recommend (motor and prop) for 2kg weights fpv flying?

    My quadcopter: SK450 with “landing gear”, KK2, turngy plush 30A, NTM Prop Drive Series 28-26A 1200kv / 286w, 1045 prop.

    First I tried to fly this config with 845 prop, but it could not take off, then I changed to 1045. It lfew for a while but I recognized the motors where to hot, and the battery also, so I stopped. I knew this config won’t enough strong for that flying but I had to try it.

    Thank you in advance!
    Regards,
    Imi

    Reply
    1. Oscar Post author

      HI,
      there is no way you can calculate the thrust of a motor accurately, unless it’s provided by the manufacturer, or measured by yourself.
      have you checked the “file” tab in the product page on Hobbyking? sometimes there is a datasheet file in there, or data from some users.
      If no, try google it, I am sure someone has measured this and share on the internet.

      NTM Prop Drive Series 28-26A – This motor seems to run best with 1060 props, each motor can generate 967g thrust for 19A at 100% throttle, so this motor should be good enough for 2KG quad.

      However, also make sure your battery’s C rating is high enough.
      Good luck!

      Reply
  55. sandeep krishna

    Thanks for ur valuable comment sir, i would also like to know what will be the flying time with 10×4.5 prop and above said configuration sir.
    And Sir as soon the buzzer of the low voltage alarm starts we need to land the quad sir?

    Reply
  56. sandeep krishna

    hi sir ,im planning to make a quad the estimated weight with components in 950g-1kg
    i planning to use 30A esc, 980 kv motor, 3300mAh battery 25c/50c(burst) which propellor to choose for this configuration sir ( weight of battery 247g)

    Reply
    1. Oscar Post author

      HI!
      I would suggest to try 9 inch and 10 inch propellers, see which is better.
      9 inch should give you better stability, but 10 inch will give you longer flight time.

      Reply
    1. Oscar Post author

      Total weight of your quad?
      Max Thrust of your motors for the battery you are using?
      Current draw of your motors?
      C rating of your battery?

      Reply
  57. mohammad ebrahiminejad

    i have read a book about quads and for blade aerodynamics and trust calculating i need some data about the propellers blade airfoil like drag and lift and some angles.
    how can i find these things?i need a datasheet.how can i find it?

    Reply
    1. Oscar

      you don’t need a university degree to build a quad, forget about “aerodynamics”. Follow what I mentioned in the post and you should be fine. usually thrust data are provided on the product page on the websites, given the size of the prop.

      Reply
    1. Oscar

      Let’s have a look.
      What is the total weight of your quad when take off, and what is the spec of your motors? (thrust at battery voltage 3.7V per cell, and current draw at that thrust). Size of your battery? (C-rating, capacity and weight)

      Reply
  58. NIDHAY S SETH

    I want to make a quad copter for HD video recording . so total weight is around 3.5 or 4 kg so i required parameter of motor , propeller size and battery required on it.

    Reply
    1. Oscar

      that’s heavy
      you are looking at motors that can produce more than 2KG of thrust each, that is going to be expensive.
      I have never built anything this big before so I can’t give you any useful advice.

      Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Are you Robot? *

I don't look at blog comments very often (maybe once or twice a week), so if you have any questions related to multirotor please post it on this forum IntoFPV.com... You're likely to get a response from me faster on there.