The smallest drone I’ve ever built

I don’t know if this is the smallest FPV quad in the world, but it is certainly going to be the smallest I’ve personally built and flown.

I plan to use 15000KV motors, paired with 31mm quad-blades or 40mm  and tri-blades propellers. This would allow me to squeeze the frame size down to 48mm and 59mm respectively – a shockingly small quad! :)

How small is this? In comparison, the tiny whoop is 64mm (motor to motor distance)! Tiny Whoop is no longer “tiny” in front of the Angry Oskie!

The overall weight of this quad is about 20g-23g excluding battery.

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From right to left: Tiny Whoop (E010), Angry Oskie 48mm and 59mm

To give you a better idea, this is how tiny the 0703 motors are compared to a standard 5″ mini quad motor (2306) :D

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Warning: this build is not for everyone, it can be very challenging for beginners due to the small size!

Brushless Micro Quad Parts List

This build will be using the following parts. You can choose other parts, but make sure the dimension are the same if you plan to use this frame.

* The F3D8 FC and Star4 ESC are shameless clones of FishPepper’s open source work without giving any credit to FishPepper.de. But unfortunately I have not been able to find other alternatives at this point, so I thought I should mention it at least.

I will explain the parts selection in a bit more detail.

CM275T AIO Camera/VTX

A pretty good FPV setup, it has very good power filtering and I didn’t have any noticeable noise in the footage when flying my quad. Voltage sag on this monster also doesn’t seem to affect the operation of the camera either. Image quality is good enough comparing to other AIO cameras. Most importantly it’s smaller and lighter than other popular AIO such as the TX01 or FX797.

RacerStar F3D8 FC

The F3D8 is my top choice for this build because it has a built-in Frsky 8ch receiver.

RacerStar Star4 4A 4-in1 ESC

Any light weight 16x16mm 4-in-1 ESC would do just fine.

RacerStar BR0703 15000KV motors

The BR0703 are the lightest available 15000KV motors at the moment. I have seems some negative reviews of these motors online saying they come unbalanced with bent shafts, and durability is poor. But for the 10 motors I ordered they all seem to work as expected over 50 flights I’ve had. The only issue I’ve found so far is that they are quite noisy.

The RacerStar BR0703 has two versions, the SE (special edition) and the non-SE. They seem to have the same spec and numbers on paper, just being different in the colour. Anyway I bought both to find out. 

Beaware that the screws that come with these motors are of different length. The non-SE version comes with M1.6 4mm screws while the SE version comes with M1.6 2.5mm screws.

2.5mm is clearly too short for this 3D printed frame, so I would recommend getting some 4mm screws from eBay if you are going for the SE version motors (\$3 for 20 last time i check). It’s good to have spare anyway.

I have tried running 40mm triblades props on these 15000KV motors and it’s working fine so far over 50 flights. If you are worried you can use lower KV version like the 12000KV but it will give you less power.

Propellers

There are two prop options for this build, 31mm or 40mm props.

The 40mm props runs quite loud on the 0703 motors, with decent  lift and flight time. It feels very similar to how an 8mm brushed quad flies, just more agile and “punchy”. The 31mm props on these motors are even louder! It sounds like an angry bee… and it’s not as powerful as the 40mm props, but it’s fun to fly such a tiny quad around the house or office :)

However, the 31mm props are mainly designed for the Tiny Whoop’s 6mm brushed motors, which has 0.8mm shafts. Therefore they won’t fit the BR0703 motor’s 1mm shaft without drilling.

I found 0.95mm drill bit is the best for the job. I tried 1mm drill bit and it’s too big. 0.9mm seems to work also but it can be hard to push the props in, even harder if you want to remove it later on.

LiPo Battery

I tested 3 batteries so far and here is the result. Note that these batteries all use LOSI connectors, and I think 300mAh to 500mAh is a good capacity range for the 40mm props. For 31mm props I think you might need smaller batteries like 200mA to 300mA (I will confirm soon)

40mm Props:


Eachine 25C 500mAh“Blue” 25C 500mAhNanoTech 45C 300mAh
Flight Time3-4 mins3-4 mins2 mins
PunchModerate to GreatModerateGreat

31mm Props:


Eachine 25C 500mAh“Blue” 25C 500mAhNanoTech 45C 300mAhEachine 150mAh
Flight Time3-4 mins2-3 mins2 minsUnflyable!
PunchPoor to ModeratePoorModerateInsufficient Power

I have not tried the popular Tiny Whoop 200mAh batteries for the 31mm props as I don’t have any, but I quite like how it flies with the 300mAh I tested.

Where to Get the Angry Oskie Frame Kit

The “Angry Oskie” frame is designed specifically for the parts we listed in this post. The whole frame can be 3D printed, except the following items which you should buy separately:

  • 4 x M2 25mm screws
  • 1 x rubber band (as battery holder)
  • a little piece of Velcro (as battery holder)

mThis build also uses a few M2 spacers and M2 nuts, but luckily, these come with the FC and ESC we use.

The Angry Oskie has 2 different sizes: 48mm and 59mm depending on what propellers you intend to use with it. (if you are not sure what these numbers mean check out our quadcopter frame guide)

Weight:

  • 59mm frame – 2.2g
  • 48mm frame – 1.7g
  • Camera mount – 0.9g

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I plan to print this frame with nylon-carbon for durability and rigidity.

All credits go to Oscarliang, many thanks to him for this frame.