Place screw heads in the channel at the top and let them roll down to sort into the baskets.

The whole screw sorter is split into a top and bottom piece that go together. The top screw sorter sorts short screws from .375" to .875". The bottom sorts screws from 1" to 2.5". If you set them next to each other, screws will roll from the top to the bottom; I just held them together with a chip clip in the front.

Doesn't work with .25" screws because they are too top heavy to fall. Longer screws sort more accurately if they are rolled from further down rather than from the top.

Print the screw sorters on their backs with supports in the openings. Print both sorters and baskets with 15% infill. There are also versions of the screw sorters with the backs cut out to save plastic.