Pitting a CFD-Optimized Toroidal Propeller Against a Conventional One
https://hackaday.com/2026/09/28/pitting-a-cfd-optimized-toroidal-propeller-against-a-conventional-one/

Although we often think that we got certain aspects of aerodynamics pretty much licked at this point, details like the optimal shape of a propeller remains hotly debated, both in- …read more (https://hackaday.com/2026/09/28/pitting-a-cfd-optimized-toroidal-propeller-against-a-conventional-one/)

Metal Gear Solid Moves From PlayStation to ESP32
https://hackaday.com/2026/09/29/metal-gear-solid-moves-from-playstation-to-esp32/

If you haven’t heard of Metal Gear, you probably haven’t played video games these last few decades. The original Metal Gear dates back to 1987 and launched on the MSX, …read more (https://hackaday.com/2026/09/29/metal-gear-solid-moves-from-playstation-to-esp32/)

Testing Coulomb’s Law and Similar Fundamentals Yourself Remains Tricky
https://hackaday.com/2026/09/29/testing-coulombs-law-and-similar-fundamentals-yourself-remains-tricky/

How easy is it to build a simple demonstration at home that proves fundamental law of physics, such as Coulomb’s inverse square law, or Maxwell’s equations? This is one of …read more (https://hackaday.com/2026/09/29/testing-coulombs-law-and-similar-fundamentals-yourself-remains-tricky/)

Geothermal Cooling For New York’s Subways
https://hackaday.com/2026/09/29/geothermal-cooling-for-new-yorks-subways/

You might think that if you dug some tunnels down into the ground where you could be out of the sunshine, that you might find them to be relatively cool …read more (https://hackaday.com/2026/09/29/geothermal-cooling-for-new-yorks-subways/)

Electromechanical TV Goes 3D with This Light-field Display
https://hackaday.com/2026/09/29/electromechanical-tv-goes-3d-with-this-light-field-display/

A mechanical TV — the kind that makes an image with a Nipkow disk and a single lamp with some help from persistence of vision — is easy enough to …read more (https://hackaday.com/2026/09/29/electromechanical-tv-goes-3d-with-this-light-field-display/)

Improved Double-Sided Toner Transfer Method
https://hackaday.com/2026/09/29/improved-double-sided-toner-transfer-method/

In the era before PCB shops would make almost any PCB imaginable, as well making many other manufacturing processes for prototypes available to hobbyists, there were several ways of making …read more (https://hackaday.com/2026/09/29/improved-double-sided-toner-transfer-method/)

Designing a Fully 3D-Printed Mechanical Calculator
https://hackaday.com/2026/09/29/designing-a-fully-3d-printed-mechanical-calculator/

Even if almost tragically impractical in a world where digital calculators are cheap as chips, mechanical calculators and their big mechanical computer brethren remain an absolute marvel of engineering. Using …read more (https://hackaday.com/2026/09/29/designing-a-fully-3d-printed-mechanical-calculator/)