I could imagine a book case or shelving unit where the adjustable shelves are held up by wooden bolts through the sides of the carcass. That would be such a cool item in a boy’s bedroom or in a bar/man cave.<grin/> I can imagine your wife / mother asking... so what are you going to use them for?
(I bet you have no answer )
I notice you are working the screwthread "dry", have you ever pre-soaked the dowel in BLO beforehand to see if this gives a better surface fininsh to the threads? I know When I make threads by hand BLO helps give a much better finish as well as making it easier to move the threadboxYou ask, we deliver)
Perhaps this link will work? The machine on camera.