Why Build a 5-Inch?
The 5-inch freestyle quad is the heart of FPV. It is the sweet spot where power, agility, and practicality converge. A well-built 5-inch can carry a full GoPro for cinematic footage, survive impressive crashes, and deliver the raw speed that makes FPV thrilling. Building your own teaches you every system intimately — when something breaks (and it will), you will know exactly how to fix it.
This guide walks through a complete 6S build with modern components. Every part choice is explained so you can substitute based on budget and availability.
Complete Parts List
- Frame: TBS Source One V5 or ImpulseRC Apex. Both are durable, well-documented, and have abundant spare parts. The Source One is open-source and budget-friendly ($30); the Apex is premium ($90) with better vibration characteristics.
- Flight Stack: SpeedyBee F7 V3 FC + 55A 4-in-1 ESC. Excellent value at $70, includes Bluetooth for wireless Betaflight configuration from your phone. The 55A rating handles any 6S motor.
- Motors (x4): T-Motor Velox V3 2207 1950KV or iFlight XING2 2207 1855KV. Both are proven performers at $20-25 per motor.
- Props (x8+): HQ Prop 5.1×4.3×3 V2S or Gemfan 51433. Buy at least 4 sets — you will break props. $3-4 per set.
- VTX: Rush Tank Solo 800mW or TBS Unify Pro32. Both support SmartAudio for pit mode and power control from Betaflight OSD. $30-50.
- FPV Camera: Runcam Phoenix 2 JB Edition or Caddx Ratel 2. Excellent low-light performance, 1.8mm or 2.1mm lens. $30-40.
- Receiver: Happymodel EP1 or Radiomaster RP1 (ELRS 2.4GHz). Ceramic antenna tower, true diversity on EP1 Dual. $13-20.
- Battery: CNHL Black Series 6S 1300mAh 100C or GNB 1350mAh 120C. Get 3-4 packs. $25-35 each.
- Miscellaneous: XT60 pigtail with low-ESR capacitor (35V 470uF or 50V 1000uF), M3 hardware kit, battery straps (250mm), U.FL/MMCX antennas, TPU parts (camera mount, antenna mount, arm guards).
Assembly Walkthrough
Step 1: Frame Prep
Assemble the frame arms to the bottom plate. Use blue threadlocker on all metal-to-metal screws. Carbon fiber edges are sharp — lightly sand arm edges to prevent wire damage. Install the press nuts if your frame uses them.
Step 2: Mount Motors
Attach motors to arms with the provided M3 screws. Threadlocker is mandatory here — a loose motor screw causes catastrophic failure. Route motor wires along the arms toward the center. Use braided sleeving or electrical tape to protect wires from prop strikes.
Step 3: Install Electronics Stack
Mount the ESC and FC using the rubber grommets and nylon standoffs provided. The ESC goes on bottom (closer to arms for shorter motor wires), FC on top.Ensure the arrow on the FC points forward — this is critical for correct gyro orientation.
Step 4: Soldering
This is the skill that intimidates beginners. Key tips:
- Use a temperature-controlled iron at 370-400C (700-750F)
- 63/37 leaded solder is much easier to work with than lead-free
- Tin both the pad and wire before joining
- Motor wires: solder to ESC pads. Wire order does not matter — motor direction is set in Betaflight.
- XT60 pigtail: solder the main battery leads to the ESC. Add the capacitor across the same pads (observe polarity — the stripe is negative).
- Keep all wires short — excess wire adds weight and catches on things.
Step 5: Peripheral Wiring
Connect camera, VTX, and receiver to the FC. Reference your FC pinout diagram. Typical connections:
- Camera: 5V, GND, Video (to CAM pad)
- VTX: 7-20V (VBAT filtered), GND, Video (from VTX pad), SmartAudio (to TX pad on a free UART)
- RX: 5V, GND, TX (to RX pad on a free UART), RX (to TX pad)
Step 6: Betaflight Configuration
Flash the latest Betaflight (4.5+). Configure:
- Ports tab: Set UART for RX as “Serial Rx”, UART for VTX SmartAudio as “TBS SmartAudio”
- Configuration tab: Set receiver mode to “Serial (via UART)” and protocol to “CRSF”
- Power tab: Set voltage/current sensor scales (from ESC specs)
- PID tab: Apply default PIDs for 5-inch
- Modes tab: Set ARM on a switch, add pre-arm if desired
- Motors tab: Test each motor, verify direction, set ordering
Step 7: Safety Checks
Before the first flight:
- Use a smoke stopper on first power-up — it will save your electronics if there is a short
- Verify motor direction in Betaflight Motors tab (props OFF)
- Check failsafe: turn off radio with quad armed (props off) — motors should stop
- Range test: walk 30m away with quad on, verify RSSI stays above 50%
- Test hover in angle mode first, then switch to acro
Building a 5-inch is a weekend project for a first-timer. Take your time on soldering — cold joints are the number one cause of in-flight failures. When you lift off for the first time on a quad you built yourself, the satisfaction is unmatched.