Eric Robb RC Eric Robb RC RC Builds · Custom Parts · Backyard Engineering
The Eric Robb Builder System

Free RC Design Tools

These aren't a random pile of calculators — they're one system. Design the airplane, choose compatible electronics, wire it correctly, check the setup, diagnose problems, and document the finished build. Each step hands off to the next. Six connected airplane-building steps, plus a specialist LED Compatibility Checker — free, no signup, and everything works on your phone at the field.

★ Flagship
Step 1 · Design

RC Airplane Designer

Enter wingspan, flying style, battery, and motor. Get your CG location, wing loading, thrust plan, and servo placement — with a to-scale 2D plan, a spinnable 3D view, and a buyable parts list.

Design my airplane →
Advanced
Step 1 · Design (deep end)

Foam Flight Lab

My deep-end design sandbox. Drag sliders and watch a 3D plane rebuild itself while it solves what the quick designer doesn't: neutral point, static margin, tail volume, stall speed, turn radius, and roll rate. Best on desktop — it works in millimetres and grams.

Open Foam Flight Lab ↗
Step 2 · Choose electronics

Electronics Checklist Builder

Answer a few questions about your plane and get a complete, buyable parts checklist — motor, ESC, battery, servos, and radio, all sized to work together.

Build my checklist →
★ Flagship
Step 3 · Wire

RC Wiring Designer

Pick your battery, ESC, receiver, and servos — see a color-coded wiring diagram for your exact setup, the right hookup order, and the mistakes that fry electronics.

Show me the wiring →
Step 4 · Calculate

RC Calculators

Center of gravity from your wing chord, plus flight time, wing loading, C-rating max current, and static thrust — quick single-purpose calculators for the numbers you check most.

Run the numbers →
Step 5 · Preflight & Diagnose

Flight Doctor

Ask in plain English why your plane won't fly and get a real answer back — reversed elevator, bad CG, backwards prop, brownout — plus the fix. Falls back to a guided version that works with no signal.

Diagnose my plane →
Step 6 · Document

Spec Sheet Maker

Document your build like a pro — fill in dimensions, electronics, and settings, add a photo, and print a clean one-page PDF spec sheet to keep or share.

Make a spec sheet →
Then

Build it & show it off

Design done? Follow the first-airplane guide, then share the result in Community Builds.

Lighting Tools

For LED builds

Have an idea for a tool that would help your builds? Tell me about it — the best suggestions get built and added here for everyone.