Drones

Custom FPV Quadcopter

Built a custom FPV drone from individual parts instead of using a ready-to-fly kit. I wired the power path, flight controller, ESC, motors, and ELRS receiver, brought it up in Betaflight, and completed initial flight testing.

Flown, tuning needed FPV Betaflight ELRS Soldering ESC Hardware bring-up

Built from individual components

ELRS + Betaflight configured

Initial flight test completed

Overview

Project Summary

A custom FPV drone build focused on wiring, power validation, receiver setup, Betaflight configuration, motor testing, flight testing, and hardware troubleshooting.

What I built

I built a custom FPV quadcopter from individual components instead of starting with a ready-to-fly kit. The build included the frame, motors, ESC, flight controller, receiver, power path, capacitor, transmitter link, Betaflight setup, bench motor testing, and initial flight testing.

Why I built it

This was my first real robotics-adjacent project. I wanted something that would actually challenge me, so instead of starting with a basic robot car or claw kit, I chose a drone. That made the project harder because the wiring, firmware, controller link, power system, and tuning all had to work together before it could fly.

System

Core Hardware

Flight controller	Holybro Kakute H7 v1.3
ESC	Holybro Tekko32 F4 4-in-1 ESC
Receiver	HGLRC Hermes 2.4 GHz ELRS
Transmitter	RadioMaster Boxer ELRS
Power	4S LiPo, XT60 pigtail, capacitor
Safety	ViFly Short Saver 2
Video	DJI Goggles 2, DJI O4 Air Unit, analog fallback hardware

Build process

What I Personally Did

Selected and assembled the main hardware stack

Wired the ESC, flight controller, receiver, XT60 pigtail, capacitor, and motor path

Checked continuity before applying battery power

Used a short-saver during first power-on

Configured Betaflight ports and receiver settings

Bound the ELRS receiver and validated receiver input

Tested motor output from the Betaflight Motors tab

Debugged UART, receiver, arming, and ESC behavior

Troubleshot an early controller / receiver pairing blocker before switching to a RadioMaster Boxer ELRS

Identified the DJI O4 compatibility issue with the selected stack

Completed initial flight testing and confirmed the drone could lift off and fly

Problems I ran into

The first major blocker was the controller and receiver link. I started with a BETAFPV LiteRadio 2 SE ELRS V3 and ran into pairing, firmware, and flashing issues. I tried multiple software and hardware-level troubleshooting paths, including bootloader / flashing attempts, but the reliable fix was moving to a RadioMaster Boxer ELRS and reworking the control-link setup from there.

The receiver did not immediately behave as expected in Betaflight. The issue was not only power or binding; the UART and serial receiver configuration also had to line up before Betaflight could see valid receiver input.

The build exposed arming blockers and ESC telemetry limitations. Motors eventually spun during bench testing, but the ESC telemetry / BLHeli32 path was not cleanly resolved.

The DJI O4 Air Unit exposed a compatibility issue. I bought it for the digital video path, but the flight-controller and video stack I chose were not a clean match. I documented it as hardware I owned, not hardware that was fully integrated into the working build.

The soldering process was affected by a tool issue: the soldering iron tip was not making reliable thermal contact. I made a temporary crimped contact repair so I could keep working while waiting on better equipment. The current soldering is documented honestly and planned for rework.

The drone did fly, but it was too sensitive for my skill level at the time. The airframe had more power than I was comfortable controlling, so the next step is tuning and controlled flight practice rather than claiming it as a polished aircraft.

What worked

• Safe first power-on process
• ESC-to-flight-controller wiring validation
• ELRS receiver bind with the RadioMaster Boxer
• Receiver data visible in Betaflight
• Betaflight configuration and motor testing
• Motors spinning during bench tests
• Initial flight test completed
• Basic staged hardware bring-up workflow

Remaining work

• PID / rate tuning for more controllable flight
• Final video path
• Exact frame, motor, prop, capacitor, and battery specs
• Betaflight config export
• Cleaner final build photos
• Reworked soldering with current tools and current skill level
• Longer controlled flight testing

Takeaway

What I Learned

This project made me better at staged hardware bring-up. I learned to test power first, then receiver input, then motor output, instead of trying to make the whole drone work at once. It also taught me that a robotics system can fail at several layers: hardware, firmware, radio link, software configuration, power delivery, or tuning. The drone eventually flew, but the control sensitivity showed me that getting a system airborne is not the same thing as having it tuned, documented, and easy to operate.

Evidence