Difficulty & Ratings Guide

Every build in this repo is rated on six dimensions. None of them are "overall difficulty" because that's a lazy metric that tells you nothing useful. A build can be dead simple to execute but genuinely dangerous, or technically brilliant but cheap and safe. The six scales tell you what you're actually signing up for.

The 6-Scale Rating System

Dimension	What It Measures	Range
Jaw Drop	Visual impact / wow factor	⭐ to ⭐⭐⭐⭐⭐
Brain Melt	Technical complexity	⭐ to ⭐⭐⭐⭐⭐
Wallet Damage	Out-of-pocket cost after salvaging	⭐ to ⭐⭐⭐⭐⭐
Spicy Level	Danger / safety risk	⭐ to ⭐⭐⭐⭐⭐
Clout Potential	Social media / bragging rights	⭐ to ⭐⭐⭐⭐⭐
Time to Build	Total build time	⭐ to ⭐⭐⭐⭐⭐

Jaw Drop Rating

Visual impact. How hard does this hit when someone sees it for the first time?

Rating	Description	Example Builds
⭐	"Huh, neat." Interesting if you explain it. Doesn't stop scrolling.	#198 Homopolar Motor, #068 RAM Stick Ruler
⭐⭐	"Oh, cool." Gets a second look. Makes someone lean in.	#184 Chain Fountain, #107 Bismuth Crystal Garden
⭐⭐⭐	"Wait, how?" Stops conversation. People pull out their phones.	#042 Grape Plasma, #016 Infinity Mirror Table
⭐⭐⭐⭐	"That's not real." Genuinely hard to believe it was built from junk.	#033 Musical Tesla Coil, #009 Rubens' Tube
⭐⭐⭐⭐⭐	"I need to rethink my life." Changes what someone believes is possible with salvaged parts.	#055 Levitating Plasma Speaker, #181 Musical Marble Machine

Brain Melt Level

Technical complexity. How much do you need to understand before you can build this?

Rating	Description	Example Builds
⭐	Follow the instructions. If you can read, you can build it.	#101 Colored Fire, #280 Density Tower
⭐⭐	Basic skills required — soldering, wiring, or simple mechanical assembly. One afternoon of YouTube gets you there.	#187 Ball Bearing Motor, #139 Pi-Hole Ad Blocker
⭐⭐⭐	Multiple skill domains. You need to understand the theory, not just follow steps. Things can go wrong in non-obvious ways.	#122 LED Cube 8x8x8, #156 Electroplating Station
⭐⭐⭐⭐	Serious engineering. You're designing circuits, debugging invisible problems, and troubleshooting failures with a multimeter and an oscilloscope.	#033 Musical Tesla Coil, #141 Face Tracking Laser
⭐⭐⭐⭐⭐	You're basically doing R&D. The build doc gets you started, but you'll be reading datasheets, solving novel problems, and iterating through failures. Nobody's holding your hand.	#036 Rail Gun, #153 Deepfake Mirror

Wallet Damage

Out-of-pocket cost AFTER salvaging what you can. Every build assumes you're scavenging hard before you spend a dime.

Rating	Cost Range	Description	Example Builds
⭐	$0	Free. Trash only. Everything comes from the junk pile.	#198 Homopolar Motor, #058 HDD Platter Wind Chimes
⭐⭐	$1–15	A few bucks for consumables — solder, wire, a chemical you can't salvage.	#101 Colored Fire, #184 Chain Fountain
⭐⭐⭐	$15–50	Real money, but nothing that hurts. Microcontrollers, specialty chemicals, specific components.	#132 ESP32 Weather Station, #107 Bismuth Crystal Garden
⭐⭐⭐⭐	$50–150	You're investing. Buying modules, sensors, structural materials, or specialty parts that don't exist in junk piles.	#088 Electric Skateboard, #123 Smart Mirror
⭐⭐⭐⭐⭐	$150+	Even with aggressive salvaging, this build costs real money. Capacitor banks, large motors, precision components.	#036 Rail Gun, #024 Electric Go-Kart

Spicy Level

Danger. This is the one that matters most. Ignore the other ratings if you want — never ignore this one.

Rating	Name	Description	Example Builds
⭐	Chill	Paper cuts and stubbed toes. The worst that happens is a minor inconvenience.	#171 Pepper's Ghost Hologram, #280 Density Tower
⭐⭐	Mildly Sketchy	Soldering iron burns, minor chemical exposure, hot glue blisters. Routine shop hazards. Respect them, but they won't send you to the ER.	#187 Ball Bearing Motor, #122 LED Cube 8x8x8
⭐⭐⭐	Respect It	High voltage, power tools, toxic chemicals. Things that punish carelessness with real injuries. You need to understand the hazards before you start.	#034 Jacob's Ladder, #110 Pharaoh's Serpent
⭐⭐⭐⭐	One Wrong Move	One mistake means a hospital visit. MOT capacitors, high-current circuits, molten metal, concentrated acids. Serious preparation required. Don't work alone.	#005 Desktop Foundry, #035 Electromagnetic Can Crusher
⭐⭐⭐⭐⭐	Call Next of Kin	Can kill you if you're careless. Lethal voltage, thermite-class reactions, capacitor banks storing enough energy to stop a heart. Read ALL safety documentation before you touch a single component.	#036 Rail Gun, #105 Thermite Flower Pot

Required safety gear by spicy level:

Spicy Level	Minimum Safety Gear
⭐	Safety glasses
⭐⭐	Safety glasses, nitrile gloves, ventilation
⭐⭐⭐	Full PPE (glasses, gloves, closed-toe shoes), multimeter, fire extinguisher
⭐⭐⭐⭐	Full PPE + face shield, rubber insulating mat, buddy system (never work alone)
⭐⭐⭐⭐⭐	Everything above + dead man's switch on circuits, hospital route planned, someone who knows what you're doing and when you're doing it

Clout Potential

Social media and bragging rights. How much attention will this get when you post it?

Rating	Description	Example Builds
⭐	Your mom likes it. That's about it.	#139 Pi-Hole Ad Blocker, #068 RAM Stick Ruler
⭐⭐	Your friends think it's cool. Gets some engagement in maker communities.	#127 Auto Plant Watering, #132 ESP32 Weather Station
⭐⭐⭐	Strangers share it. Solid Reddit/TikTok material. "That's actually sick."	#042 Grape Plasma, #016 Infinity Mirror Table
⭐⭐⭐⭐	Goes semi-viral. People who don't care about building things share it because it looks unreal.	#009 Rubens' Tube, #033 Musical Tesla Coil
⭐⭐⭐⭐⭐	Main character energy. The algorithm picks it up. News outlets repost it. Your DMs don't recover.	#055 Levitating Plasma Speaker, #053 Singing Ferrofluid Tornado

Time to Build

From first teardown to final test. Assumes you have the tools and materials ready.

Rating	Time Range	Description	Example Builds
⭐	Under 1 hour	Quick hit. Set up, build, film, clean up. One sitting.	#198 Homopolar Motor, #101 Colored Fire
⭐⭐	1–4 hours	An afternoon project. Start after lunch, done by dinner.	#184 Chain Fountain, #042 Grape Plasma
⭐⭐⭐	4–12 hours	A full day or a couple evenings. You'll sleep on it at least once.	#122 LED Cube 8x8x8, #156 Electroplating Station
⭐⭐⭐⭐	1–3 weekends	Multi-session build. You'll have a work-in-progress on your bench for a while. Plan for iterating and debugging.	#033 Musical Tesla Coil, #182 Stirling Engine
⭐⭐⭐⭐⭐	Multi-weekend marathon	This is a campaign, not a project. Weeks of work across multiple sessions. The kind of build that earns a dedicated shelf in your shop.	#036 Rail Gun, #181 Musical Marble Machine

Danger Level Deep Dive

The spicy level rating is the only one that can put you in the hospital. Here's exactly what each level looks like, what hazards it includes, and what you need on hand before you start.

flowchart TD
    S1["⭐ Chill"] --> G1["Safety glasses"]
    S2["⭐⭐ Mildly Sketchy"] --> G2["Safety glasses\nGloves\nVentilation"]
    S3["⭐⭐⭐ Respect It"] --> G3["Full PPE\nMultimeter\nFire extinguisher"]
    S4["⭐⭐⭐⭐ One Wrong Move"] --> G4["Full PPE + face shield\nRubber mat\nBuddy system"]
    S5["⭐⭐⭐⭐⭐ Call Next of Kin"] --> G5["Everything above\nDead man's switch\nHospital route planned"]

    style S1 fill:#22c55e,color:#fff
    style S2 fill:#84cc16,color:#000
    style S3 fill:#eab308,color:#000
    style S4 fill:#f97316,color:#fff
    style S5 fill:#ef4444,color:#fff

Specific hazards by level:

Level	Hazards You'll Encounter	What "Going Wrong" Looks Like
⭐ Chill	Sharp edges, minor pinches, hot glue drips	Band-aid territory
⭐⭐ Mildly Sketchy	Soldering iron burns (350-400C), mild chemical skin irritation, small cuts from wire and sheet metal	A blister, a rash, or a nick that bleeds for a minute
⭐⭐⭐ Respect It	Mains voltage (120/240V), angle grinder kickback, toxic fumes, corrosive chemicals	Burns, lacerations, chemical exposure that needs flushing, electrical shock that hurts but doesn't kill
⭐⭐⭐⭐ One Wrong Move	MOT output (2000V+), molten metal splashes, concentrated acid spills, high-current arcs, spinning machinery	Deep burns, broken bones from kickback, acid burns requiring medical treatment, cardiac disruption
⭐⭐⭐⭐⭐ Call Next of Kin	Capacitor banks (lethal energy storage), thermite (4000F), rail gun projectiles, high-energy electromagnetic discharge	Electrocution, severe burns over large areas, shrapnel injuries, fires that can't be conventionally extinguished

The golden rule: If you're not sure which spicy level you're comfortable with, build a few ⭐⭐ projects first. Learn what "being careful in a shop" feels like before you touch anything that doesn't forgive mistakes.

What Should I Build First?

Pick your row. Build the thing. Come back for more.

You Have	Comfort Level	Start With
Nothing	Curious	#198 Homopolar Motor
Basic hand tools	Beginner	#184 Chain Fountain
Soldering iron	Ready	#042 Grape Plasma
Multimeter + solder	Intermediate	#009 Rubens' Tube
Full toolkit	Confident	#033 Musical Tesla Coil
Everything	Fearless	#055 Levitating Plasma Speaker

The progression isn't arbitrary. Each build teaches you the skills and safety instincts the next one requires. Skipping ahead is how people get hurt or get frustrated. Start where you are. The hard stuff isn't going anywhere.