🏗️ Mechanical & Kinetic

Where scrap metal, magnets, and gravity conspire to create motion from nothing.

This category is for builds that move, spin, oscillate, or transfer energy through purely mechanical or electromagnetic means. No code, no circuits (mostly) — just physics doing its thing with junkyard parts.

Common salvage sources: Ball bearings, copper pipe, scrap metal, old bed frames, syringes, neodymium magnets from dead hard drives, bike parts, gears from printers.

Builds

Suggested Build Order

Start with passive physics demos, progress toward precision machines:

1. #186 — Eddy Current Brake — Magnet + metal = invisible braking force.
2. #187 — Ball Bearing Motor — Simple magnetic interaction. Minimal assembly.
3. #184 — Chain Fountain — Pure kinetic chain dynamics. Zero electronics.
4. #190 — Prince Rupert's Drop — Molten glass quenching phenomena.
5. #316 — Pendulum Wave Machine — Precisely tuned pendulums creating wave patterns.
6. #183 — Hydraulic Robot Arm — Syringe-based hydraulic actuators.
7. #189 — Curie Engine — Temperature-dependent magnetic phase transitions.
8. #182 — Stirling Engine — External combustion heat engine.
9. #185 — Trebuchet — Projectile mechanics and energy transfer.
10. #188 — Magnetic Gear Train — Non-contact magnetic gearing precision.
11. #181 — Musical Marble Machine — Mechanical sequencing + musical tuning. The masterpiece.

Related Categories

• Raspberry Pi & Arduino — Motor-driven automation and robotics
• Junkyard Auto — Drive mechanics and power transmission
• Art & Installation — Kinetic sculptures and display pieces

📚 Reference Guides

• Tools Needed
• Sourcing Guide
• Difficulty & Ratings Guide