So this is the first time I build a “toothpick” style micro quad from scratch and not buying a pre-built kit :) This should be fun as I get to choose my own hardware!
- Frame: Diatone Cube GTB229
- FC/ESC/VTX: HGLRC FD413 FC Stack (F4 FC, 13A 4in1 ESC, 400mW VTX)
- FPV Camera: Runcam Racer Nano
- Motors: iFlight XING Nano 1103 8000KV
- Props: HQ Micro Prop 65mm Bi-Blade
- Receiver: Frsky XM+
Diatone sent me a spare frame for their Cube GTB229 micro quad, so I decided to use it for this custom build. Middle one in the below picture.
It has a unique “box” style structure with very skinny arms, and yet the arms are cut from 3mm thick carbon fibre which makes it relatively strong. But it’s not indestructible as I’ve broken one before. The good thing about it is the light weight and stiffness.
Diatone didn’t send me the canopy, but you can get the STL file from their website and print your own. I printed mine in black TPU.
It has a cool canopy design including a mount for dipole antenna.
The only problem with this frame is the lack of motor screws. Normally motors should come with motor screws, but when you have a frame with unusually thicker arms then it’s handy to provide those special motor screws required.
The two sets of screws that come with the motors are either too short or too long. So if you are going to use this frame, make sure you get yourself some M2 6mm screws for the motors.
Flight controller Stack
I picked the HGLRC Micro FC stack is because it also comes with a VTX. Product page : http://bit.ly/2kKoEsU (10% off coupon: oscarliang)
It comes with the following accessories.
Some close up of the boards:
One of the questions when choosing an FC is whether it has a powerful enough 5V BEC. Because literally everything in a 2.5″ micro quad runs off 5V, including RX, FPV camera and VTX. It puts a lot of stress on the 5V BEC and if the 5V BEC on the FC isn’t strong enough, it will eventually damaged the board.
The VTX is the most “amp hungry” device, and if the FC stack comes with an VTX, at least you don’t have to worry about it.
The ribbon cable connecting between FC and 4in1 ESC has wrong color coding (reversed). Not a big deal, you can just ignore the connect it anyway.
And the “manual” are printed way too small, you might need a magnifying glass to read it :(
One thing I would rather see in this stack is the removal of all the plastic connectors, and just “direct solder” all the wires between the boards. These connectors raise the height of the stack considerably which makes it harder to build in these small micro quads.
Soldering and connecting all the components, before mounting them in the quad.
Only after I mounted everything nicely in the frame, I realized I made a mistake. I mounted the FC with the USB port facing back and it gets blocked by a standoff so I can’t plug it into the computer without taking the canopy off… never mind…
With the VTX comes with the FC stack, things cannot get simpler for my FPV setup.
There are currently only two nano FPV cameras I would considered worth spending money on: the Runcam Nano 2 and the Racer Nano. Between the two I probably favour the Nano 2 a bit more because it’s much cheaper. But you can change camera setting on the Racer Nano so it’s a bit more powerful. Product page: https://bit.ly/2vKBSrC
I will do a comparison of all the nano cameras in the future.
Motors and Props
I have never tried the XING motor line up from iFlight, but I have heard many good things about them from my local FPV group. They have a round motor bell instead of the traditional cylinder shape which is very unique in drone motors.
iFlight scaled down this design and made the XING Nano 1103 8000KV motors, and with the colorful paint job they look absolutely sick! Product Page: http://bit.ly/2kkq6SH
Note that they don’t have prop mounting holes on the top of the bell, so they are really only for “push on” propellers.
Take Away – What can be done better?
Looking back, there are things that can be done better in this build.
Building one of these micro quads requires more patience than building a 5″ racing drone. Everything is smaller, especially the soldering part, is much harder.
Not only should you plan the connection and wiring beforehand, also look at your frame and plan FC and ESC board orientations. Don’t get your USB port blocked like mine!
If you build a lot of these 2″, 2.5″ and 3″ micro quads, get some spare M2 bolts of various lengths, they will come in handy!
The weight of this build is 53 grams, which is heavier than expected. I think there are a few ways to make it lighter.
Firstly, shorten the wires as much as you can, every gram counts! Pressed wires between boards also defeats the purpose of soft mounting. If necessary, go back and re-do the wires after you’ve built and tested it.
Avoid using steel hardware but nylon whenever possible.
Use rubber band instead of “proper” LiPo strap – I could probably save 2-3 grams there alone especially the one I use has a metal buckle :)