FarmCraft101 (repairs/restoration, woodworking and useful tips) - https://www.youtube.com/c/FarmCraft101

KYLE.ENGINEERS (aero and car tech) - https://www.youtube.com/c/KYLEDRIVES/

Machine Thinking (history of machining) - https://www.youtube.com/c/machinethinking/

Greg's Airplanes and Automobiles (historical, technical deep dives) - https://www.youtube.com/channel/UCynGrIaI5vsJQgHJAIp9oSg/

Huygens Optics (optics history and manufacture) - https://www.youtube.com/c/HuygensOptics/

w2aew (RF electronics and tutorials) - https://www.youtube.com/user/w2aew/

Aaron Lanterman (electronic classes, esp audio) - https://www.youtube.com/c/Lantertronics/

MicroType Engineering (electronics and pcb design) - https://www.youtube.com/c/MicroTypeEngineering/

Project Farm (unbiased tool/hardware reviews) - https://www.youtube.com/c/ProjectFarm/

Tod's Workshop (historical weapons) - https://www.youtube.com/c/TodsWorkshop1

rctestflight (RC stuff) - https://www.youtube.com/c/rctestflight