Sub 250 3" Apex mini with DJI O3

By D4N13L on Jun 08, 2023

5  92  4

Hi there,
i got hyped for building my own drone after buying the Avata. It is a nice drone but i want to go more into freestyle.
My target was to build a 3 inch, sub 250 fpv but compatible with my DJI Goggles Integra and DJI FPV Remote 2.

Some Information:
This frame combined with the O3 air unit only allows a maximum camera angle of around 30°. The metal pins are blocking a more agressive angle.
The props are ok for a beginner like me and with default betaflight settings. In the future, i definately need some with a higher pitch for faster response.
The overall weight is 256g :-(
Flight time (cruising on higher altitude, with some powerloops, flips and a little wind) is around 8 min.

It war a lot of fun to build it and it will not be the last one for sure.
Thanks for all the inspiration i found on!


Part List


APEX Mini 3 Zoll 150mm Carbon Faser Rahmen Kit mit 4MM Dicke Arme Für FPV Freestyle RC Racing drone Quadcopters

Flight Controller

F411 Mini HD + KO25 BLHeli_S Stack By Skystars
See Site


4 x Emax ECO Micro Series 1404 - 3700KV Brushless Motor
See Site


HQProp Durable T3X1.8X3 PC - 1.5mm (2CW+2CCW)
See Site

FPV Camera

DJI O3 Air Unit (4 builds)
See Site


Tattu 4S 850mAh 75C Lipo Battery (XT30) (3 builds)
See Site
Show stores (3)


Sign in to comment

uomobionico   Sep 18, 2023  

hi, very nice build.
how did you secure the O3 to the frame?
did you double tape glue it ?
do you have any videos on how it flies ?

D4N13L   Sep 18, 2023 

thank you very much
I double tape glued (
) it and used a zip tie as well.
Sorry but I have not recorded a video how it flies so far. But it flies like a charm and is very durable as well. Flew against a couple of trees and a excravator without damaging more than the props.


uomobionico   Sep 18, 2023 

thanks so much for prompt response.
hopefully soon I will replicate your build.
would it be possible to have a picture to see how far the O3 ends up inside the frame towards the FC/ESC and at the back towards the spacers

D4N13L   Sep 18, 2023 

sure here you go
the o3 unit is all the way in the back and touching the spacers
between o3 unit and FC/ESC stack there are 1,5cm space only.

Guides & Reviews

Jun 21, 2021

AirbladeUAV has done it again and this time they've brought long range to the 5" class! Based on the popular Transformer Mini, the new Transformer 5" Ultralight adopts a lot of the same design philosophies with larger props and more payload capacity. It can fly upwards of 20 minutes on a 4 cell Li-Ion battery pack and in ideal conditions it's got a range of over 4 to 5 miles. In this guide I'll walk..

Read more
Mar 04, 2021

With the release of the DJI FPV Drone cinematic FPV has become a lot more accessible, but you certainly don't want to crash a $750 drone! The QAV-CINE Freybott is a compact, lightweight cinematic FPV drone that can take a hit and keep going. It's a lot safer to fly indoors and around people. With a naked GoPro or the SMO 4k you can capture some great stabilized footage. In this guide I'll show you..

Read more