RotorX Switchback - BrainFPV Radix Li Rebuild

By Wholelottanope on Jun 30, 2019

12  281  1

This is an update to a previous build ( ) which was due for a rebuild after the Zeus FC caught fire as they are prone to do.

I went with a BrainFPV Radix Li and Spedix 4-in-1 ESC combo and changed up the way the structural stack worked. With the FC and ESC both using silicone bobbins with M3 holes I was able to use M2 hardware with brass nut hardware (most of it was from Runcam Split Mini hardware packages) to create a solid link between the carbon. This made for an exceptionally easy, not awkward build. A complete departure from the old style of spacers and loose fitting sandwiched gear.

The BrainFPV Radix Li is running their own version of Betaflight with their updated version that displays the Crossfire link stats. So unbelievable.
I'm using the usual RX1404 3600kv motors on 3" props and it's exceptionally quiet as well as being under 250g which lifts alot of the restrictions on where you can and can't fly now in Canada (thanks TC).

Control and video link are left to TBS Crossfire Nano radio link and a TBS Unify 5G HV SE MMCX VTX with a Runcam Eagle Micro camera up front. With this being a gopro hauler it doesn't need to suffer the video feed you usually have to fly through if you use a Runcam Split Mini. The Eagle Micro feed is fantastic.

Hopefully the pictures help with anothers build process.



Part List


RotorX Switchback 3 Inch Frame Kit (10 builds)

Flight Controller

RADIX LI Flight Controller - brainfpv (2 builds)


Spedix IS25 25A 5S 4-in-1 ESC


4 x RotorX RX 1404 3600kV 3S-4S Brushless Motor (3 builds)


RotorX Triblade RX 3044TX Props (3CW, 3CCW) (31 builds)

FPV Camera

RunCam Micro Eagle (221 builds)

FPV Transmitter

Team BlackSheep TBS UNIFY PRO 5G8 HV SE (MMCX)


Lumenier Micro AXII MMCX 5.8GHz Antenna (RHCP) (2 builds)


TBS Crossfire Nano RX (SE) (229 builds)


Tattu 11.1V 3S 850mAh 75C LiPo FPV Battery - XT60 (11 builds)


TBS Tango (11 builds)


Ocr TM 120pcs M2 Brass Spacer Standoff Screw Nut Assortment Kit (M2)

Misc Parts

Full Speed Lucky Box Buzzer (5 builds)
Show stores (7)


Sign in to comment

robbson   21 days ago  

Sweet build! Flight footage?

Guides & Reviews

35 4,047  38
May 31, 2019

A couple years ago I built the TransTEC Frog and since then I've been patiently waiting for another TransTEC frame to catch my eye. Fast forward to today and the TransTEC Laser S is that frame. It's a 82g racing frame that features 6mm arms, a TPU micro cam mount, 30.5mm and 20mm stack mounts and 3K carbon and 7075 hardware. My goal here was to build a high quality 6S racer at a reasonable price. I'd..

Read more
Apr 17, 2019

This is the 4th installment to my popular "Wizard Killer" series, and is based on the popular Wizard X220HV 6S. As usual, the goal was to build a substantially better quad, yet come in below the retail price of the BNF kit. Here are some of the improvements: Higher quality EMAX ECO 2306 1700kv motors Foxeer's top-of-the-line Falkor mini camera Eachine 25mw-1000mw Leaf VTX with microphone Tools This..

Read more