Review: Flycolor X-Tower Stack | FC & 4in1 ESC

by Oscar

This is the first time I review products from Flycolor – the X-Tower stack. I was impressed with the performance and value of their BLHeli_S Rapter ESC’s, so I am looking forward to testing their latest offering.

Some of the links on this page are affiliate links. I receive a commission (at no extra cost to you) if you make a purchase after clicking on one of these affiliate links. This helps support the free content for the community on this website. Please read our Affiliate Link Policy for more information.

Where To Buy?


What’s Special about the X-Tower Stack?

The X-Tower is a dual-board stack, an F4 flight controller and 4in1 BLHeli_32 ESC board.

It comes with probably the most complete set of accessories in all the flight controllers and stack systems I have used. It’s just missing a buzzer :)

It’s priced at $78 which is nearly $10 cheaper than the Kakute F4 with Tekko32 4in1 ESC’s.



Specifications of the FC

  • F405 Processor, MPU6000 Gyro
  • BEC: 3.3V (for Spektrum RX), 5V and 12V
  • 6 UART’s
  • Betaflight OSD
  • Micro SD card slot for Blackbox (support up to 32GB)

There is no solder pads on this flight controller, it uses only JST-style connectors. It’s made to be paired with the 4in1 ESC.

There are JST connectors on both sides of the board. The SD card slot is located on the bottom side.

Specifications of the 4in1 ESC

  • BLHeli_32 Firmware
  • Current Rating: 40A (45A Burst)
  • Supports 3S-6S voltage input
  • Built-in Current sensor (Single shut resistor)

Unfortunately ESC telemetry is not supported on this ESC board.

Build quality actually looks pretty good and there are lots of caps for noise filtering as you would expect on any good ESC’s these days.


I am testing the X-Tower stack on my Martian Mini Quad build.

To be honest, there is nothing groundbreaking here about this stack, F4 FC with BLHeli_32 seem to be the norm these days. However it is cheaper than some of the popular options out there. If it performs well in my testing then it might be worth considering.

JST Connectors

Personally, I am not a fan of the plastic JST connectors. Because I am replacing the FC and ESC on an existing quad, it means I had to solder connectors on all the wires in order to plug them in to the FC. It’s a lot of extra work if you are coming from FC’s with solder pads.

There is benefit, however, in using connectors. You don’t have to solder at all if you are replacing with another X-Tower FC. That’s probably useful for racers, who break FC more often and this allows them to fix their quad more quickly in the field.

Building & Soldering

Apart from the connectors, there are a few minor things I’d like to point out.

The solder pads on the 4in1 ESC are quite close to the FET’s, it makes soldering a bit harder as you have to pay extra attention not to damage the FET’s with your hot iron and solder.

The PDB silkscreen is hard to read, luckily the manual that comes with it is very well written.

The 4in1 ESC cable is too short if you decide to rotate the ESC or FC 90 degree / 180 degree.

Flycolor assigned 12V for both camera and VTX as power supply. if you have a camera or VTX that only takes 5V, you would have to route the 5V from another connector… It gets messy. that’s one of the reasons why I prefer solder pads.

Gyro’s power supply (3.3V) is broken out to an external pad and intended to be shared with other devices (like the spektrum RX). This might or might not be a problem, but I think it would be better for the Gyro to have it’s own dedicated power supply.


Leave a Comment

By using this form, you agree with the storage and handling of your data by this website. Note that all comments are held for moderation before appearing.


Terry Luther 30th May 2022 - 6:16 pm

How do I connect flysky fli14+ ibus reciever to flycolor raptor f4 stack. Can’t get reciever to work.

Tanis Palma 22nd September 2020 - 8:50 pm

I got the raptor-s tower f4 f.c. can any one tell how to use or explain the s5 and s6 pins are for?

Jlu 25th August 2020 - 7:48 am

I have a flycolor x-tower that came with my arris x-speed chameleon 220, and my led wires were cut so I connected the motor directly to by pass the led line the manufacturer said to but I get nothing from the esc or fc? Would u have an idea what could be going on?

WESLEY CRUTCHFIELD 28th November 2019 - 11:55 am

hi guys i need help, i bought one for my first build, i plan to use the R9, im bound ok but nothing in the stick tab, i then tried with an XM+, bound ok but same problem, no sticks no RSSI comming back, what have i done wrong, i recall on other F4’s there was a shorting solder pad but i cant see anything here,…. HELP, my first build is desk bound.

Oscar 1st December 2019 - 4:44 pm

it should be plug and play (i don’t think there are solder bridges, it’s been too long i don’t remember).
If no luck, join our forum we will help you troubleshoot:

Nate 6th August 2019 - 8:03 pm

Hi. I have this FC and am desperately trying to figure out which wires of the new DJI FPV box goes to where on the FC. Can you shed any light on this?

Andrea 4th January 2019 - 12:18 am

Hi Oscar, are you aware of any specific issue in connecting telemetry with frsky receiver?
I tried everything, including softserial, but seems no data are passing..

jasper 26th January 2019 - 10:10 pm

did you find it? im still looking

Ayhan 13th December 2018 - 7:00 am

Hi Oscar,

i have installed the x-tower to my new racer.

the dsmx port is without power, no matter what i do, i want to use it with a dsmx sat, in betaflight everything is set so far.
do you have an idea for me?

thank you!!!

Oscar 13th December 2018 - 2:25 pm

have you tried checking with multimeter?
maybe join IntoFPV for technical troubleshooting :)

Roy 5th March 2019 - 10:51 am

I ran into the same issue with my X-tower. using spectrum DSMX sat receiver. Bound it to my radio with regular receiver on the model for the quad. set it for serial rec and spectrum DSMX in Betaflight. plugged in sat rec to board radio turned on and powered on the light on sat rec. checked power and ground to sat rec on board . 3.3v.
after trying this and that,finally noticed that the power wire going to the board was actually the signal input on the board. so swapped signal and power wires on the connector and plugged it back in,radio on and powered on the board. light on in the sat rec. connected to Betaflight and all controls working. So basically the power input and signal input on this board are reversed as to the wiring of the spectrum sat rec. Hope this helps someone.

Peter 14th October 2018 - 6:58 pm

Do you know where I would connect an rssi input to this board?. I’m using an irangex rx801 receiver in s bus mode.
I have a wire attached to pin 28 on the receiver which is apparently rssi out on this receiver.

Oscar 23rd October 2018 - 4:47 pm

It doesn’t have an RSSI input on the FC. You’d have to pass RSSI via a SBUS channel.

dcseek 8th October 2018 - 4:25 pm

hi, I have a question: when you are talking about soldering motor’s wires you told to pay attention not to damage the FET’s, but on schematics they show to mount the ESC with the other side up so I would not solder near FETs. Is it ok to solder on the other side?
your reviews are great man!