
Micro Scisky: A 32-bit Open-Source Brushed Flight Controller - demouser7
https://dronegarageblog.wordpress.com/2016/09/25/micro-scisky-the-32bits-open-source-brushed-flight-controller/
======
flexd
This article is very outdated. Small brushless quadcopters are readily
available now. Such as the Hoverbot Nano [1] mentioned in another commment, or
a Eachine Lizard [2], and lots more.

And you can go even smaller, such as a pepperfish [3]

This is a small brushless quad with 0703 motors with a 1 cell battery.
[https://i.imgur.com/EdFFfsc.png](https://i.imgur.com/EdFFfsc.png) /
[http://rotaro.no](http://rotaro.no) 54mm in diameter

[1] [https://hoverbot.io/](https://hoverbot.io/) [2]
[https://www.banggood.com/Eachine-Lizard95-95mm-F3-FPV-
Racer-...](https://www.banggood.com/Eachine-Lizard95-95mm-F3-FPV-Racer-
BNF-4-in-1-10A-ESC-OSD-5_8G-48CH-25MW100MW-VTX-600TVL-
Camera-3S-p-1141589.html) [3]
[http://fishpepper.de/projects/pepperf1sh/](http://fishpepper.de/projects/pepperf1sh/)

~~~
rimliu
And there are Tiny Whoops with BetaFlight compatible FCs.

------
the_real_sparky
The brushed designs have been completely outclassed by the new breed of micro
brushless quads. The Hoverbot Nano is one of the best examples of lightweight
brushless design.

[https://hoverbot.io](https://hoverbot.io)
[https://www.rcgroups.com/forums/showthread.php?2806620-Hover...](https://www.rcgroups.com/forums/showthread.php?2806620-HoverBot-
Nano-40g-Brushless-90mm-Quadcopter)

~~~
anfractuosity
Cheers, that looks very interesting. I'm just wondering what are the main
advantages of brushless vs brushed motors for quads. Do brushless let you
control the speed of the propellers more easily?

~~~
LeifCarrotson
Brushed motors are around 75% efficient, brushless are around 90% efficient.
This has two effects: obviously, you get more flight time from your battery
with a more efficient motor, but that's not the main effect. The big one is
that power output is limited by the combination of how much heat you can
remove (which is roughly the same, perhaps 20W) and how efficient your motor
is. With a 90% motor, your 20W of heat max means you can have 180W of thrust,
while on a 75% motor the same 20W of heat only corresponds to 60W of thrust!

Brushless motors need some high-speed switching electronics to control the
motor, swapping from one set of coils to the next at just the right frequency.
Brushed motors are stupid easy - just connect two wires, and the voltage
corresponds to torque (and thus speed). Any hobbyist could build a brushed
controller in their sleep, but it takes a lot of dedication and engineering to
design a brushless controller. Typically, this complexity is abstracted away
from the end user in a prepackaged Electronic Speed Controller, but most micro
quads integrate the ESCs on the control boards.

Brushless motors are more expensive than brushed motors. They're arguably less
complex, but we've had many years to figure out how to build super cheap
brushed motors, and can make them very small and very cheap.

In general, brushless motors are so much superior that you shouldn't even
consider brushed motors in a quad (unless you need to hit a $19.99 price
point), but do recall the cube-square law: Length squared is area, length
cubed is volume. Area corresponds to propeller swept area or wing area and
thus lift, while volume times density is equal to the weight. This is why a
hummingbird or sparrow can dart around, while a swan requires a running start
and a turkey needs to sprint and buffet (yum) the air with its wings just to
get airborne for a few seconds and roost in a tree overnight. And it's why a
$19.99 plastic micro quad with brushed motors will fly just fine, but to lift
a DSLR you'll need brushless motors and carbon fiber.

~~~
anfractuosity
Cheers, that's very interesting! I didn't realise there would be a difference
in efficiency of that much.

------
jonkrause
with the recommended parts, minus the camera/vtx combo ($20), your total is
roughly $70. for $60 you could get an eachine qx90 which is almost identical.

or you could even get much, much better quality/control out of a brushless
build with the babyhawk, which goes for around $100

if you're new to flying drones, i wouldn't recommend this at all

------
dod9er
When seeing the components the first thing that came to my mind was
"outdated", afterwards I saw the article is from 2016. If someone is
interested in a more sophisticated approach he might want to check out the
RotorX Atom: [https://rotorxracing.com/products/rx122diypr-atom-diy-kit-
wi...](https://rotorxracing.com/products/rx122diypr-atom-diy-kit-with-
rx1306-motors)

~~~
lloyd-christmas
This article is about a $70 DIY open source project, and you compare it to
buying a $400 snap and fly drone with proprietary software?

------
sargun
How does this compare to the Crazyflie 2.0? (See:
[https://www.bitcraze.io/crazyflie-2/](https://www.bitcraze.io/crazyflie-2/)).

~~~
9demon
In terms of hardware it is practically the same. However Crazyflie has its own
development while these cheap controllers can work with any standard open
source flight software such as Cleanflight, Betaflight, etc. They are also
cheaper than Crazyflie, you can have a drone for half the money.

------
jaboutboul
Sure looks like the little bugger from the Slaughterbots video to me.

------
smcl
Does anyone know what kind of battery life can you expect for the suggested
components - it seems the linked battery is 380mAh

------
iDemonix
Looks like a fun project, be interesting to see a video of how well it flies.

------
jamcrust
They are doing a lot of similar things over at Noisebridge in SF right now.

