diy engineering

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.

DIY Perks shows how to turn old or smashed TVs and monitors into realistic artificial window lights, using the backlight and Fresnel lens to simulate distant daylight.

DIY Perks builds a webcam mod using a two-way mirror in a box so the camera sits behind the screen image. This allows real eye contact on video calls.

DIY Perks shows how to modify devices that use older USB connectors so they charge and connect over USB Type-C. He solders in a USB-C connector board and works through cases such as dongle-dependent gadgets and a mouse receiver.

A step-by-step guide to building a lifter, a small triangular ionocraft made from balsa wood, aluminum foil and thin wire, powered by a high-voltage supply. It also shows high-voltage safety practices.

A woodworker shows how his table saw accident happened, why it happened and how to avoid a similar one. He describes severe hand lacerations from a blade contact.

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.

A beginner-focused tutorial on freehand knife sharpening with a single stone, aiming for a shaving-sharp edge in about five minutes.

Jeri Ellsworth shows step by step how to make an NMOS transistor at home using a kiln, rust remover, spin-on dopant, eBay wafers and vinyl stickers.

Ben Krasnow of Applied Science shows how to make and test YBCO high-temperature superconductor with a kiln and eBay chemicals. He demonstrates flux pinning and shows a close-up of the crystal structure.