engine design

Bisqwit builds a Doom or Duke Nukem 3D style software-rendered 3D engine in C from scratch, supporting non-Euclidean geometry. It covers vector rotation and portal rendering with sped-up, tool-assisted coding.

A 1930s Chevrolet training film explaining the principles and development of the differential gear. It builds the idea step by step from first principles to the finished mechanism.

Mathologer shows a simple idea, the commutator, that lets anyone who can solve the first layer design their own full Rubik's cube solution. The same idea carries over to other symmetric twisty puzzles such as the Megaminx.

Shawn Hymel of DigiKey introduces KiCad and explains how printed circuit boards are manufactured. It is the first part of a beginner series that builds a 555 badge project.

A 1953 US Navy training film on the basic mechanisms in fire control computers: shafts, gears, cams and differentials. It shows how these mechanical parts compute ship and target firing solutions.

A motorcycle safety video on the SMIDSY (sorry mate, I didn't see you) accident, explaining the perception and optical illusion that makes drivers fail to see riders, and how riders can spot the signs and avoid it.

The first episode of Clickspring's series building a John Wilding skeleton clock from raw stock in a home machine shop. It covers making the frames along with the tools needed for the job.

A guide to charging a non-Tesla EV, here a BMW i4, at a Tesla Supercharger in the UK, with do's and don'ts. It shows the process in practice now that the network is open to all cars.

Bisqwit writes a NES emulator in C++ in about 15 minutes of tool-assisted, sped-up coding, narrated with captions. It shows an accurate emulator built with a compile-time generated 6502 instruction table. Part 2 covers compiling and running it.

Lock-picking YouTuber Bill Johnson (BosnianBill) explains how to choose a high-security lock and why, showing examples and comparing designs. It covers what makes some padlocks more pick-resistant than others.

This Old House's Ross Trethewey explains MERV filter ratings and how air filtration works, then shows how to build a localized DIY air filter, including a box fan with multiple filters.