Skill Trees

Pick a path. Start at the bottom. Work your way up. Every build teaches you something the next build needs.

This isn't a random list of projects. It's a progression system. Each path starts with something anyone can build in an afternoon and ends with something that'll make a professional engineer raise an eyebrow. The skills compound — what you learn in build #1 is the foundation for build #4.

Pick the path that excites you most and start at the beginning. Don't skip ahead. The early builds are easy on purpose — they're teaching you the skills that keep you alive (and successful) on the hard ones.

Electrical Path

Theme: Understanding voltage, current, magnetism, and the invisible forces that make everything work.

flowchart LR
    A["#198 Homopolar Motor"] --> B["#187 Ball Bearing Motor"] --> C["#242 LED Jacket"] --> D["#122 LED Cube 8x8x8"] --> E["#034 Jacob's Ladder"] --> F["#033 Musical Tesla Coil"] --> G["#037 Coil Gun"] --> H["#036 Rail Gun"]
    style A fill:#22c55e,color:#000
    style B fill:#22c55e,color:#000
    style C fill:#22c55e,color:#000
    style D fill:#eab308,color:#000
    style E fill:#eab308,color:#000
    style F fill:#ef4444,color:#fff
    style G fill:#ef4444,color:#fff
    style H fill:#7c3aed,color:#fff

Side quests: #038 Electromagnetic Levitator, #035 Electromagnetic Can Crusher, #186 Eddy Current Brake, #199 Lenz's Law Slow-Mo Magnet

Pyro & Chemistry Path

Theme: Controlling chemical reactions, understanding combustion, and making things glow, burn, and explode (safely).

flowchart LR
    A["#101 Colored Fire"] --> B["#102 Elephant Toothpaste"] --> C["#103 Smoke Bomb Array"] --> D["#113 Steel Wool Photography"] --> E["#104 Cold Spark Machine"] --> F["#110 Pharaoh's Serpent"] --> G["#109 Luminol Crime Scene"] --> H["#105 Thermite Flower Pot"]
    style A fill:#22c55e,color:#000
    style B fill:#22c55e,color:#000
    style C fill:#eab308,color:#000
    style D fill:#eab308,color:#000
    style E fill:#eab308,color:#000
    style F fill:#ef4444,color:#fff
    style G fill:#ef4444,color:#fff
    style H fill:#7c3aed,color:#fff

Side quests: #115 Permanganate Auto-Ignition, #116 Calcium Carbide Cannon, #111 Chemiluminescent Fountain, #007 Fire Tornado Table, #120 Dry Ice Bubble Cauldron

Coding & Automation Path

Theme: Using microcontrollers and code to make physical things smart, responsive, and autonomous.

flowchart LR
    A["#139 Pi-Hole Ad Blocker"] --> B["#132 ESP32 Weather Station"] --> C["#127 Auto Plant Watering"] --> D["#128 ESP32-CAM Security"] --> E["#123 Smart Mirror"] --> F["#141 Face Tracking Laser"] --> G["#144 Sentiment Room Lighting"] --> H["#153 Deepfake Mirror"]
    style A fill:#22c55e,color:#000
    style B fill:#22c55e,color:#000
    style C fill:#eab308,color:#000
    style D fill:#eab308,color:#000
    style E fill:#eab308,color:#000
    style F fill:#ef4444,color:#fff
    style G fill:#ef4444,color:#fff
    style H fill:#7c3aed,color:#fff

Side quests: #130 AI Doorbell, #149 Voice Home Automation, #143 AI Photo Booth, #134 Pirate Radio, #155 AI Dungeon Master

Mechanical & Kinetic Path

Theme: Gears, levers, thermodynamics, and the beauty of things that move.

flowchart LR
    A["#184 Chain Fountain"] --> B["#190 Prince Rupert's Drop"] --> C["#185 Trebuchet"] --> D["#183 Hydraulic Robot Arm"] --> E["#189 Curie Engine"] --> F["#182 Stirling Engine"] --> G["#043 Kinetic Wind Sculpture"] --> H["#181 Musical Marble Machine"]
    style A fill:#22c55e,color:#000
    style B fill:#22c55e,color:#000
    style C fill:#eab308,color:#000
    style D fill:#eab308,color:#000
    style E fill:#eab308,color:#000
    style F fill:#ef4444,color:#fff
    style G fill:#ef4444,color:#fff
    style H fill:#7c3aed,color:#fff

Side quests: #188 Magnetic Gear Train, #186 Eddy Current Brake, #044 Anti-Gravity Water Fountain, #025 Scooter Motor Lathe

Chemistry & Electrochemistry Path

Theme: Growing crystals, plating metals, etching surfaces, and controlling chemical reactions with electricity.

flowchart LR
    A["#107 Bismuth Crystal Garden"] --> B["#161 Copper Crystal Tree"] --> C["#213 Density Tower"] --> D["#156 Electroplating Station"] --> E["#158 PCB Etching Station"] --> F["#157 Anodizing Setup"] --> G["#160 Electroforming Art"] --> H["#109 Luminol Crime Scene"]
    style A fill:#22c55e,color:#000
    style B fill:#22c55e,color:#000
    style C fill:#22c55e,color:#000
    style D fill:#eab308,color:#000
    style E fill:#eab308,color:#000
    style F fill:#ef4444,color:#fff
    style G fill:#ef4444,color:#fff
    style H fill:#7c3aed,color:#fff

Side quests: #162 Electrochemical Etching, #165 Rochelle Salt Crystal, #163 pH-Reactive Paint, #164 Sodium Silicate Demos, #168 Thermochromic Mug

Light & Optics Path

Theme: Lasers, plasma, optics, and everything that glows, refracts, or projects.

flowchart LR
    A["#171 Pepper's Ghost Hologram"] --> B["#177 UV Mineral Display"] --> C["#016 Infinity Mirror Table"] --> D["#018 Shadow Chandelier"] --> E["#175 Camera Obscura Room"] --> F["#017 Laser Fog Projector"] --> G["#172 Schlieren Optics"] --> H["#173 Fiber Optic Star Ceiling"]
    style A fill:#22c55e,color:#000
    style B fill:#22c55e,color:#000
    style C fill:#eab308,color:#000
    style D fill:#eab308,color:#000
    style E fill:#eab308,color:#000
    style F fill:#ef4444,color:#fff
    style G fill:#ef4444,color:#fff
    style H fill:#7c3aed,color:#fff

Side quests: #176 Laser Maze, #174 Polarization Art, #178 Light Painting Robot, #022 Holographic Fan Display, #023 UV-Reactive Water Wall

Sound & Music Path

Theme: Making noise, music, and instruments from salvaged parts.

flowchart LR
    A["#235 Cigar Box Guitar"] --> B["#241 Bottle Xylophone"] --> C["#012 Thunder Drum"] --> D["#056 Hard Drive Speaker"] --> E["#124 Arduino Guitar Pedal"] --> F["#008 Plasma Speaker"] --> G["#009 Rubens' Tube"] --> H["#135 MIDI Stepper Organ"]
    style A fill:#22c55e,color:#000
    style B fill:#22c55e,color:#000
    style C fill:#22c55e,color:#000
    style D fill:#eab308,color:#000
    style E fill:#eab308,color:#000
    style F fill:#ef4444,color:#fff
    style G fill:#ef4444,color:#fff
    style H fill:#7c3aed,color:#fff

Side quests: #011 Ferrofluid Speaker, #014 Bone Conduction Speaker, #013 Aeolian Wind Harp, #236 PVC Pipe Organ, #239 Steel Tongue Drum

Fabrication & Metalworking Path

Theme: Progression from hand tools to a full machine shop, built entirely from salvage.

flowchart LR
    A["Hand Tools"] --> B["#080 Hand Drill Press"] --> C["#026 Belt Grinder"] --> D["#027 Spot Welder"] --> E["#005 Desktop Foundry"] --> F["#082 Table Saw"] --> G["#219 Alternator Welder"] --> H["#025 Scooter Motor Lathe"] --> I["#069 Printer Stepper CNC"]
    style A fill:#22c55e,color:#000
    style B fill:#22c55e,color:#000
    style C fill:#22c55e,color:#000
    style D fill:#eab308,color:#000
    style E fill:#eab308,color:#000
    style F fill:#eab308,color:#000
    style G fill:#ef4444,color:#fff
    style H fill:#ef4444,color:#fff
    style I fill:#7c3aed,color:#fff

Side quests: #081 Sawzall Power Hammer, #028 Powder Coating Oven, #029 Vacuum Former, #031 Silent Compressor

Cross-Path Builds

The best projects live at the intersection of multiple skill trees. Once you're at stage 3-4 in two paths, you're ready for these combo builds:

How to Use This Page

1. Pick one path. Whichever one makes your brain light up.
2. Start at stage 1. Even if you think you're beyond it. The early builds are fast, cheap, and teach fundamentals you'll need later.
3. Don't rush. Spend time understanding WHY each build works, not just HOW to assemble it.
4. Cross paths. Once you're at stage 3-4 in one path, start stage 1 in another. The best builds combine skills from multiple paths.
5. Side quests are optional but rewarding. They reinforce the same skills from a different angle.

The endgame builds aren't gatekept by money or access — they're gatekept by skill. The skill tree is how you earn your way there.