FPV Construction Helper

Overview

FPV Construction Helper is a web application designed for FPV drone builders who want to make informed decisions when selecting components. The application provides a set of calculators for performing flight-related calculations and tools for comparing parts, helping pilots understand how different components will interact before making a purchase.

The idea for the application came from discussions within the FPV community, where builders often need to manually calculate parameters like motor KV ratings, propeller tip speeds, and thrust-to-weight ratios. By centralizing these calculations in one place, the tool makes the drone building process more accessible to newcomers while providing experienced pilots with quick reference calculations.

Technical Details

Architecture

The application is built with Angular 18 following a modular architecture pattern:

• Core Modules - Navigation and configuration services
• Features Modules - Calculators and rates charts functionality
• Shared Modules - Reusable components like calculator templates and data tables

The user interface uses Angular Material components with Tailwind CSS for styling, featuring a dark theme optimized for indoor use during late-night builds.

Calculators

The application includes six specialized calculators:

Acceleration Calculator - Computes drone acceleration in m/s² based on single motor thrust, total weight, and motor count. This helps builders understand how their drone will perform during aggressive maneuvers.

Optimal KV Rating Calculator - Determines the ideal motor KV rating for a given propeller size and battery configuration. Uses the Mach number concept to calculate propeller tip speed and derives the appropriate KV rating to stay within safe operating limits.

Power to Weight Ratio Calculator - Calculates the thrust-to-mass ratio (T/M) for the entire drone. This is a critical metric for flight performance - drones with ratios above 1:1 can fly inverted, while 2:1 or higher provides aggressive freestyle performance.

Propeller Tip Speed (PTS) Calculator - Computes the speed at which propeller tips travel through the air. This calculation accounts for environmental losses and helps builders avoid exceeding safe tip speeds that cause efficiency loss and excessive noise.

RPM Calculator - Determines motor RPM based on battery voltage, KV rating, and estimated efficiency losses. This provides realistic RPM values accounting for real-world inefficiencies.

PTS Converter - Converts between different propeller sizes while maintaining the same tip speed. Useful when switching between propellers and wanting to preserve flight characteristics.

Rates Charts

The rates charts feature implements Betaflight rate calculations and actual rates visualization. Pilots can input their rate, super rate, and expo values to see how the stick response curve will behave in flight. This helps fine-tune flight characteristics without flashing firmware.

Key Features

• Six specialized FPV calculators covering thrust, KV, RPM, and tip speed
• PTS converter for propeller size migration
• Interactive rates charts with visual curves
• Dark theme interface optimized for workshop environments
• Responsive design for use on mobile devices during builds
• Modular architecture enabling easy addition of new calculators

Lessons Learned

Working on FPV Construction Helper provided valuable insights into FPV drone mechanics. Before this project, my understanding of drone flight characteristics was largely theoretical. Implementing the calculations forced me to deeply understand how motor KV, battery voltage, propeller size, and thrust relate to each other.

I learned how propeller tip speed affects efficiency and why high-KV motors on large props can be wasteful. The KV rating calculator taught me the relationship between Mach numbers and safe propeller operation - tip speeds exceeding approximately 0.9 Mach cause significant efficiency losses due to blade stall effects.

The thrust calculations revealed how motor thrust specifications relate to overall drone performance. Understanding that thrust scales with propeller size, RPM, and motor characteristics helped me appreciate the engineering tradeoffs in drone design.

Beyond the FPV domain, this project reinforced my Angular architecture skills, particularly in building reusable calculator components that share consistent behavior while implementing different calculations. The modular approach allows new calculators to be added without duplicating UI code.

This project demonstrated that building tools for hobbies I participate in creates motivation for quality implementation. When you understand the domain deeply, you can build more useful tools that actually solve real problems faced by practitioners.