Paul Hopewell humbly explaining and showing his design considerations, machining process and final fail of an interesting build (32:19 video):
https://www.youtube.com/watch?v=8n_RmygA2E8
His cheap and simple (though labor intensive) DIY solution of cutting 10-100T gears (of any PCD) on a shaper (29:29 video):
https://www.youtub e.com/watch?v=7De17gyX2sU
