Flysky FS-i6X Button Box v2

Background

Many droid builders active today have likely heard of the Kyber system.  Kyber adds several additional inputs to a standard R/C transmitter, which are generally used for triggering sounds and animations.  The system (excluding the newer EthOS based setups) works by replacing one of the potentiometers on the radio transmitter with a series of momentary buttons, housed in a 3D printed “button box”.  The necessary signals are read and processed by the Kyber main board through SBUS compatible R/C receivers such as the FrSky RX8R.  This allows one R/C channel to carry the data for as many as 15 buttons (potentially more with alterations to the circuit).

I wanted to use a similar setup for a droid that was already controlled by the Flysky FS-i6X, adding my own iBus based processing system on the droid side.  I had a bare Kyber button board PCB and I got it working with the Flysky radio, but I needed a way to mount the actual buttons to the radio, so I designed some mount parts to attach everything.  

Ultimately, however, I changed direction to use my own custom board with PCB-soldered buttons instead, housed in a box between the gimbals.  This printable is that box housing.

In spite of the name, this would likely work just as well on any similar radio; there's nothing actually Flysky-specific in this printable.

What You Will Need

• A Flysky i6X radio

• A correctly wired PCB with 15 PCB-mounted buttons.  My buttons are spaced roughly 15.5 mm horizontally and 12.75 mm vertically.  Note that mine are slightly offset vertically from the center of the PCB, so there's a right way up for putting the PCB into the housing.

• A drill with a bit (for making the hole to insert the wires that connect the PCB to the radio)

• A hot glue gun and/or M2.5 screws (I think … whatever screws work with the PCB mounting holes)

• Some tape or a hinge or something similar.  Used to attach the housing to the radio.

Note that this document only covers assembly of the PCB into the mount, not wiring the PCB or connecting it to the radio.  (If you join the Mouse droid builder's club, my build thread has much more detail on that part of the project.)

Just as a pointer, though, to assemble the button circuit itself, you would need to obtain a similar PCB, resistors, wire/jumpers, soldering supplies, and the necessary normally open and momentary pushbuttons.  My new version of the circuit is built on an Elegoo 5 x 7 cm protoboard from this pack and these PCB mounted buttons.  There are sixteen 330 ohm resistors and one 10k ohm resistor.  Should you choose to undertake this project, I highly recommend using quality buttons for this, not cheap Amazon/Aliexpress specials.  I now strongly suspect that all of my issues with custom buttons were not due to the circuit, but due to the actual buttons being flaky.

Assembly

Assembly is pretty simple.  

1. There's a right way up for my board because the buttons are slightly offset from center.  You can figure the correct orientation out by putting the buttons into the holes from the outside first so that the buttons are reasonably centered in their holes, then seeing how well the four corner holes on the PCB align with those in the Button_Box.  Whichever way makes both the screw holes and the button holes line up the best is the right way up.

2. Insert the PCB into the housing with the buttons facing the holes and the board turned the right-way up.

3. Now you need to hold the PCB in place.  Option 1: Use screws in the four corners of the PCB.  Option 2: Press the Button_Box_Retainer part into the Button_Box so that it holds the PCB in place, then put some hotglue in the corners to hold the retainer in place.  Option 3: Both.

4. Use tape or some sort of hinge to attach the Button_Box to the radio.  I used a piece of gaffer tape along the top edge on the inside and another on the outside, forming a sort of living hinge.

Note

This part was originally button box v1, but I have renamed it to v2 as of 2026 to make the revision history more clear (because strictly speaking the box included in my original attempt was v1).  More importantly, if you are using the official Kyber button board that has buttons already mounted to a PCB (as I am now doing) you should instead use the new v3 model that I will be posting soon.