How to build the lightest Ardupilot microquadcopter 3-inch "2-stack" frame?


This is part 1 of a 3" Ardupilot micro quadcopter build, starting by making a custom light frame able to carry all of the electronics and cameras of a full fledge drone:
-A F7 Ardupilot (ChibiOS) autopilot
-a FPV camera
-Video live tx 5.8Ghz
-Full HD video recording (1920x1080 30 fps)
-Mavlink radio telemetry (real time telemetry on ground control station)
-GPS + Compass
-2S 3300 mah Li-Ion battery for long flight time (to be tested)

The frame is designed to carry two full 30x30 stacks (and has screwholes for 20x20 stacks).

The frame has a protective top plate, so is not only a unprotected base plate exposing the electronics.

This custom frame is a composite made of plywood, carbon fiber elements and balsa/carbon fiber sandwich plate.Such a composite allows to get a much lighter frame than its equivalent in full carbon with the same, if not better rigidity.

The result is a frame with 50% of the weight of the lightest two stacks 3" carbon fiber frame that exist on the market at this time.

A part 2 will be cover the microcopter build…

STL files of the frame:
Frame bottom: FrameBottom.stl (455.6 KB)

Frame top: FrameTop.stl (254.8 KB)

UPDATE 1 : I tested two different 4-in-1 ESCs board in order to find one that will allow to be powered by a 2S battery while running BlHeli32 which seems to be a challenge as suppliers all pretend they support 2S when not true…

UPDATE 2: I decided to use the Kakute F7 autopilot in the build because this autopilot has a SD card slot to record the Ardupilot logs. It also has 6 available UARTS which are needed to connect all of the equipment (receiver, GPS, radio telemetry, etc…)

UPDATE 3 : I forgot Holybro specifies the Kakute F7 as a 3S minimum board which would ruin my decision to use this board with a 2S battery. So I tested what is the real minimum voltage supported by the board:

UPDATE 4 (09 feb 2019) : Here is finally the build video:



Nice Hugues, waiting the second part :slight_smile:


really great project I fancy having a go at this Hugues,could you please put a parts list up and would you have a file of the frame please,many thank’s

What do you think about 3d printing the frame?

1 Like

Very nice, I’ve wanted to build your 300 class frame since you posted it. Very interested in seeing the electronics and how you mount them.

1 Like

Now I would also be interested in his 300 class frame as that is what I fly at the moment

I added the STL files to download.


To what email can I send them ?

1 Like

Thank you,ive sent you a message

In preparation of the microbuild, I have selected this board as the autopilot:


Voltage test of Kakute F7 in preparation of the build:


What GPS and compass will you use?

I wil use the GPS+compass : Matek M8Q-5883

1 Like

And here is the build video, finally


Have you measured flighttime / hover current already?

1 Like

We will have to wait until next video to know…

1 Like

UPDATE : PID tuning of a 3" Arducopter (2S Li Ion):


Nice Hugues:) did you check endurance?

NOt yet as the ship was unflyable when I tried. I had to tune the PIDs first. Endrance check will happen soon now, waiting for ideal weather conditions.

Did you change filters or use standard ones? Perhaps if you rise them you can have better performance