<p>Theoretically, I don’t see why we couldn’t make current motors even smaller than they are today - we already have brushless motors with stators less than 10mm across (for example <a href="https://www.banggood.com/IFlight-XING-0802-2200017000KV-1-2S-1mm-Shaft-Brushless-Motor-for-RC-Drone-FPV-Racing-p-1611286.html?ID=556194&amp;cur_warehouse=CN" rel="nofollow noreferrer">these</a> 0802 motors), and we could change the format by using inrunner motors instead. However there are certain factors that we need to consider.</p>

<p>The first of these is that we can’t just have the motors - we also need the ESC boards. This is either done with a 4-in-1 ESC or 4 individual ESCs. This adds complexity, weight, size and heat buildup.</p>

<p>We must also consider whether or not these negatives outweigh the positives. This is up to personal opinion, and in some instances it may well be worth it, however with miniaturisation comes increases manufacturing complexity with smaller tolerances.</p>

<p>These are all important factors to consider: is it possible and is it worth it.</p>

<p>I believe it is possible, however finding enough demand may be a limiting factor.</p>

CC BY-SA 4.0
2020-05-02T23:28:25.473Z
2020-05-03T18:10:52.447Z
2020-05-03T18:10:52.447Z
Drones and Whatnot
<p>For toy drones, almost the entire thing is the power system. So a smaller drone needs less battery, smaller speed controllers and a smaller frame. The only part that doesn't change is the receiver and flight controller, which are already tiny - so the drone can be shrunk until you reach the limits of motor miniaturisation or the Rx/FC become a significant part of the weight.</p>

<p>Brushless motors tend to be used on FPV quads, where the extra power is useful. They have to carry a camera and video transmitter (and more complex brushless ESCs). There's no point making the motors smaller because they need to be large enough to carry the payload.</p>

CC BY-SA 4.0
2020-05-04T09:10:48.337Z
2020-05-04T09:10:48.337Z
Robin Bennett
<p>It is also worth mentioning that the smaller the motor is the less convenient it is to change propellers. If the motors are so tiny that threaded holes won't fit the only option is to press fit the props. Due to the construction of brushless motors it can be challenging to make a shaft that is both light and can withstand the force of push. If you can't fit the propellers properly they can slip and make the craft unflyable, but it's also likely that the shaft gets pushed through the motor.</p>

CC BY-SA 4.0
2020-05-04T17:02:18.003Z
You could make a smooth brushless motor shaft so that this argument is moot, no? It would be just like regular push-on, friction-held props for micro quads.
ifconfig
CC BY-SA 4.0
2020-05-05T07:04:37.880Z
@ifconfig Honestly, I don't see how you could make a shaft for press fitting that lets you mount and remove the propeller without damaging the shaft or the propeller during the process and at the same time don't let the propeller slip. Without the option of using screws, you can't have both ways I think: it is either hard to mount/remove or will be a bit loose. Those propeller removal tools that come with these tiny motors aren't too much of a help either IMHO.
3k-
CC BY-SA 4.0
2020-05-04T09:32:04.703Z
2020-05-04T09:32:04.703Z
3k-
<p>At the top of <a href="http://microflierradio.com/brushlessmotors.html" rel="nofollow noreferrer">this</a> page (sorry no direct link to the product) they have a 0.15g brushless motor. Unfortunately it only produces 0.4g of thrust, so it can barely lift itself. To maintain a thrust to weight ratio of 1.5:1 you would need to find propellers, battery, flight controller, and radio electronics that weigh 0.4666g. There may be more tiny brushless motors, but it seems that at least with this one, the benefits of a brushless motor come down with size.</p>

CC BY-SA 4.0
2020-05-07T14:17:35.667Z
2020-05-07T14:17:35.667Z
Luca Scheuer
<p>I have seen many tiny brushed drones, about an inch from motor to motor, and was wondering whether it would be possible to create a brushless drone that small. Are there any brushless motors available that are extremely small, ones that could fit on the size of drone below? And is there anything else to consider if making a drone so small?</p>

<p>(I realize that you could put oversized motors on a small drone but I am asking about motors that would be proportionally normal)</p>

<p><a href="https://i.sstatic.net/73NrC.png" rel="noreferrer"><img src="https://i.sstatic.net/73NrC.png" alt="Small drone"></a></p>

<brushless-motors><under-250-grams>
Are there any extremely small brushless drone motors?
Jacob B
# Are there any extremely small brushless drone motors?

(Asked by: username_0 on 2020-05-02)

I have seen many tiny brushed username_1, about an inch from motor to motor, and was wondering whether it would be possible to create a brushless drone that small. Are there any brushless motors available that are extremely small, ones that could fit on the size of drone below? And is there anything else to consider if making a drone so small?

(I realize that you could put oversized motors on a small drone but I am asking about motors that would be proportionally normal)

[![Small drone](https://i.sstatic.net/73NrC.png)](https://i.sstatic.net/73NrC.png)

**Tags:** brushless-motors, under-250-grams


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## 4 answers

### Answer by username_1 on 2020-05-02. Score: 3 | Accepted answer

Theoretically, I don’t see why we couldn’t make current motors even smaller than they are today - we already have brushless motors with stators less than 10mm across (for example [these](https://www.banggood.com/IFlight-XING-0802-2200017000KV-1-2S-1mm-Shaft-Brushless-Motor-for-RC-Drone-FPV-Racing-p-1611286.html?ID=556194&cur_warehouse=CN) 0802 motors), and we could change the format by using inrunner motors instead. However there are certain factors that we need to consider.

The first of these is that we can’t just have the motors - we also need the ESC boards. This is either done with a 4-in-1 ESC or 4 individual ESCs. This adds complexity, weight, size and heat buildup.

We must also consider whether or not these negatives outweigh the positives. This is up to personal opinion, and in some instances it may well be worth it, however with miniaturisation comes increases manufacturing complexity with smaller tolerances.

These are all important factors to consider: is it possible and is it worth it.

I believe it is possible, however finding enough demand may be a limiting factor.


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### Answer by username_2 on 2020-05-04. Score: 3

For toy username_1, almost the entire thing is the power system. So a smaller drone needs less battery, smaller speed controllers and a smaller frame. The only part that doesn't change is the receiver and flight controller, which are already tiny - so the drone can be shrunk until you reach the limits of motor miniaturisation or the Rx/FC become a significant part of the weight.

Brushless motors tend to be used on FPV quads, where the extra power is useful. They have to carry a camera and video transmitter (and more complex brushless ESCs). There's no point making the motors smaller because they need to be large enough to carry the payload.


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### Answer by username_3 on 2020-05-04. Score: 3

It is also worth mentioning that the smaller the motor is the less convenient it is to change propellers. If the motors are so tiny that threaded holes won't fit the only option is to press fit the props. Due to the construction of brushless motors it can be challenging to make a shaft that is both light and can withstand the force of push. If you can't fit the propellers properly they can slip and make the craft unflyable, but it's also likely that the shaft gets pushed through the motor.

> **Comments:**
> **username_4**: You could make a smooth brushless motor shaft so that this argument is moot, no? It would be just like regular push-on, friction-held props for micro quads.  
> **username_3**: @username_4 Honestly, I don't see how you could make a shaft for press fitting that lets you mount and remove the propeller without damaging the shaft or the propeller during the process and at the same time don't let the propeller slip. Without the option of using screws, you can't have both ways I think: it is either hard to mount/remove or will be a bit loose. Those propeller removal tools that come with these tiny motors aren't too much of a help either IMHO.  

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### Answer by username_5 on 2020-05-07. Score: 2

At the top of [this](http://microflierradio.com/brushlessmotors.html) page (sorry no direct link to the product) they have a 0.15g brushless motor. Unfortunately it only produces 0.4g of thrust, so it can barely lift itself. To maintain a thrust to weight ratio of 1.5:1 you would need to find propellers, battery, flight controller, and radio electronics that weigh 0.4666g. There may be more tiny brushless motors, but it seems that at least with this one, the benefits of a brushless motor come down with size.


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