Here’s a step by step guide on how to build the @QUADMULA Siren F5 S2 (Series 2) which can fit the DJI O4 Pro. This is one of the easiest 5inch builds mainly because Quadmula give you everything you need and the frame is easy assemble and repair if needed.
I’ve been flying the previous version of this frame with a similar build for the past year and I didn’t get a chance to make a video tutorial on how to build one.
Do check out @MurdersFPV who got me onto these frames and got me started with building quads so I wanted to pay his inspiration forward. He's also an incredible freestyle pilot so well worth subscribing to!
Parts (All non-affiliate links to original company, buy them locally if you can to save on shipping/tariffs.
Disclaimer: I'm not a sponsored pilot, I didn't get any of this stuff for free and I bought everything with my own money at full price this is just what I use to build 5-inch freestyle quads. None of these companies have asked me to make a video on this build or have seen this video before it went live on YouTube.
Quadmula Siren F5 S2 Frame (Split version) -
https://quadmula.com/products/siren-f5-s2 - I ordered this with the fixed 25 degree camera mount, arm guards and the Gopro mount
DJI O4 Pro -
https://store.dji.com/ch/product/dji-o4-air-unit-pro?vid=180741 T-Motor Velox Freestyle 5inch power system -
https://www.tmotorhobby.com/goods-1390-TMOTOR+Velox+5+Inch+Freestyle+Power+System.html- This pack comprises of
- T-motor Velox F7 SE 50A stack
- T-motor Velox V3 2207 1950kv Motors (x4)
- T-motor T5146 Propellers (x4) - not used in this build
Ethix Watermelon Propellers (I like this but any 5inch 3 blade props will do) -
https://ethixltd.com/portfolio/ethix-s3-watermelon-props/Radiomaster RP1 ELRS receiver pack -
https://www.radiomasterrc.com/products/rp1-expresslrs-2-4ghz-nano-receiverThe @QUADMULA official 3D print files are all on printables
https://www.printables.com/model/1278495-quadmula-siren-f5-s2Optional extra 3D Prints
The optional ELRS RP1 antenna mount I used in this build -
https://www.printables.com/model/801488-radiomaster-rp1-v2-mount-for-quadmula-f5-splitThe optional DJI O4 stubby mount I will be changing this over to in the future:
https://www.printables.com/model/1174077-quadmula-f5f5-mini-antenna-mounts-for-dji-o4-proTimestamps
00:00 - Introduction
02:20 - Parts you need
07:26 - Tools you need
10:55 - Quadmula Siren F5 S2 Frame
19:25 - DJI O4 Pro mounting
23:54 - Dry fitting the T-motor Velox SE Stack
27:52 - DJI O4 Pro antenna
31:36 - Prep the ESC for soldering
35:50 - Prep the FC - it’s easy
37:19 - Solder the XT60
41:26 - How to solder double capacitors
49:35 - Final fit the ESC
49:59 - Add the Motors
57:57 - Add the ELRS receiver
01:02:51 - Adding the flight controller
01:05:11 - Test with a Multimeter
01:06:32 - Test with a smoke stopper
01:07:10 - Initial Betaflight set up
01:15:53 - Bind ELRS with your radio
01:14:57 - Betaflight set up 2
01:23:04 - DJI O4 Pro activation
01:24:32 - DJI binding
01:24:48 - Add ELRS Antenna
01:28:23 - Final touches
01:30:08 - Final weight
01:30:30 - The Finished Quadmula Siren F5 S2
01:30:48 - The first flight