See screws.scad for how to make screws using the specification parameters ... You can also specify your own trapezoid parameters. For ACME threads see acme_threaded_rod(). d1 Bottom outside diameter ...

The table is not all wood, of course; metal bushings and pins are used in the scissor mechanism, and the lift drive is a stout Acme-thread screw and nut. We’re impressed by [Marius]’ joinery ...