Building Your First 5-Inch FPV Drone

Table of Contents

1. Why Build Your Own
2. Parts List
3. Tools Required
4. Assembly Process
5. Soldering Guide
6. Flight Controller Setup
7. First Flight Checklist

Why Build Your Own

Building your own FPV drone offers several advantages:

• Learn the technology: Understand every component
• Easier repairs: Know exactly how to fix crashes
• Customization: Build for your specific needs
• Cost effective: Often cheaper than pre-built
• Community: Join the DIY FPV community

Parts List

Frame

Recommended: 5-inch freestyle frame (200-230mm)

• Budget: GEPRC GEP-Mark4 ($40)
• Mid-range: iFlight Nazgul 5 V2 ($50)
• Premium: TBS Source One V5 ($70)

Key features: 4-5mm arms, camera protection, battery strap slots

Flight Controller + ESC Stack

All-in-One: Simplifies wiring, saves space

• Budget: MAMBA F405 MK2 40A ($70)
• Mid-range: JHEMCU GHF420AIO 45A ($90)
• Premium: Speedybee F7 V3 50A ($110)

Specs needed: F4/F7 processor, 35A+ ESC, DShot600 support

Motors

Size: 2207 or 2306 motors, 1700-2500KV

• Freestyle: 1700-1900KV (more torque)
• Racing: 2300-2600KV (higher top speed)

Recommended: T-Motor F60 Pro IV 2207 1750KV ($100 for set of 4)

Propellers

• 5-inch tri-blade: Smooth flight, good efficiency
• HQProp 5x4.3x3: Popular beginner choice
• Buy 10+ sets: You will break many learning

FPV Camera

Specifications: 2.8mm or 2.5mm lens, CCD or CMOS sensor

• Analog: Caddx Ratel 2 ($25)
• Digital ready: Foxeer Razer Mini ($30)

Video Transmitter (VTX)

Analog:

• Rush Tank II 5.8GHz ($35) - 25-800mW adjustable

Digital:

• DJI O3 Air Unit ($230)
• Walksnail Avatar ($150)

Receiver

ELRS recommended for 2025:

• BETAFPV ELRS Nano 2.4GHz ($15)
• ExpressLRS EP2 ($20)

Battery

Spec: 4S 1300-1800mAh LiPo

• Budget: CNHL 4S 1500mAh 100C ($25)
• Premium: Tattu R-Line 4S 1550mAh 120C ($40)

Buy 4-6 batteries for extended flight sessions

Tools Required

Essential

• Soldering iron (TS100 or Pinecil recommended)
• Solder (60/40 or lead-free)
• Wire cutters/strippers
• Hex driver set (1.5mm, 2.0mm, 2.5mm)
• Multimeter
• Heat shrink tubing

Helpful

• Third hand/PCB holder
• Flux
• Solder wick
• Tweezers
• Hot glue gun

Assembly Process

Step 1: Frame Preparation

1. Inspect frame for damage
2. Install standoffs on bottom plate
3. Thread motor wires through arms
4. Attach arms to bottom plate with screws

Step 2: Motor Installation

1. Secure motors to arms (use Loctite on screws!)
2. Route motor wires neatly under arms
3. Leave ~5cm wire length for ESC connection
4. Check motors spin freely

Step 3: Stack Assembly

1. Install FC/ESC stack on standoffs
2. Use soft mounting grommets for vibration dampening
3. Orient FC with arrow pointing forward
4. Secure with screws (don't overtighten)

Step 4: Soldering Motors to ESC

Motor Wire Order: Check ESC manual, typically:

• Pad 1 (M1) → Top right motor
• Pad 2 (M2) → Bottom right motor
• Pad 3 (M3) → Bottom left motor
• Pad 4 (M4) → Top left motor

Soldering tips:

• Tin both wire and pad first
• Use 380-400°C temperature
• Quick contact (2-3 seconds)
• Inspect for cold joints

Step 5: Power Wiring

XT60 connector to FC stack:

1. Solder XT60 pigtail to ESC power pads
2. RED → Battery + (BAT+)
3. BLACK → Battery - (BAT-)
4. Use thick wire (14-16AWG)
5. Add capacitor to reduce noise (1000uF 35V)

Step 6: Camera & VTX

Camera:

1. Mount in camera mount (angle 15-30°)
2. Connect to FC or VTX:
   • RED → 5V
   • BLACK → GND
   • YELLOW → Video signal

VTX:

1. Mount on top plate or stack
2. Connect to FC UART (for SmartAudio/Tramp)
3. Power from filtered 5V or direct battery
4. Secure antenna and keep clear of carbon

Step 7: Receiver

1. Mount receiver (away from carbon fiber)
2. Connect to FC UART:
   • VCC → 5V
   • GND → GND
   • TX → RX
   • RX → TX
3. Position antenna for best reception

Soldering Guide

Good Solder Joint

• Shiny, smooth finish
• Concave "volcano" shape
• Complete pad coverage
• No cold joints or cracks

Common Mistakes

• Too cold: Dull, grainy appearance
• Too hot: Burnt pads, lifted traces
• Too much solder: Blobs, bridging
• Too little: Weak connection

Practice First

Use scrap wire and old boards to practice before working on expensive components!

Flight Controller Setup

Step 1: Betaflight Connection

1. Install Betaflight Configurator
2. Connect FC via USB
3. Update to latest Betaflight firmware
4. Load default PID tune

Step 2: Configuration

Ports Tab:

• Enable UART for receiver
• Enable UART for VTX (if SmartAudio/Tramp)

Configuration Tab:

• Set ESC protocol to DShot600
• Motor poles: 14 (most common)
• Enable bi-directional DShot if supported

Receiver Tab:

• Set to Serial-based (CRSF for ELRS)
• Test all channels respond correctly

Modes Tab:

• Configure ARM switch
• Add ANGLE/HORIZON modes for learning

Motors Tab:

• ⚠️ REMOVE PROPS
• Test motor direction
• Correct direction in Betaflight or reverse 2 motor wires

First Flight Checklist

Pre-Flight Safety

• ✅ Props removed during all bench tests
• ✅ Battery fully charged
• ✅ Receiver bound and responding
• ✅ All switches tested
• ✅ Motors spinning correct direction
• ✅ Failsafe tested (turn off radio, drone should disarm)

First Power-Up

1. Double-check all wiring
2. Plug in battery (no props!)
3. Listen for abnormal sounds
4. Check for hot components
5. Test arm/disarm
6. Test motor spin direction in Betaflight

First Hover Test

1. Install correct props (check rotation direction!)
2. Start in ANGLE mode
3. Choose open outdoor area
4. Gradually increase throttle
5. Small, controlled movements
6. Land if anything feels wrong

Post-Flight

• Check for hot motors (warm is OK, too hot to touch is problem)
• Inspect frame for loose screws
• Check props for damage
• Review flight footage if applicable

Common Build Issues

Drone Won't Arm

• Check switch configuration in Betaflight
• Verify receiver is bound
• Check CLI for error messages
• Ensure gyro is calibrated

Motors Not Spinning

• Check ESC power connections
• Verify DShot protocol settings
• Test ESC with multimeter
• Check for blown ESC (magic smoke smell)

Video Static/Noise

• Check camera and VTX connections
• Add capacitor to power leads
• Keep camera and VTX power separate
• Check antenna connection

Link Quality Issues

• Position receiver antenna away from carbon
• Check receiver orientation
• Verify UART wiring (TX↔RX)
• Update receiver firmware

Learning Resources

• YouTube: JoshuaBardwell, MrShutterBug, UAVFutures
• Forums: Reddit r/Multicopter, IntoPFV
• Discord: FPV community servers
• Practice: Use simulator before flying real drone

Remember: Everyone crashes. Expect to replace props, arms, and components. Build extra margin into your budget!

--- Last Updated: December 2025