because first machine to cut screws was built in 1568 by a French mathematician, Jaques Besson. The first nuts and bolts appeared in the middle 1400's. The bolts were just screws with straight ...

This isn’t to say belts won’t work — you can create a fine CNC machine with bits of rubber. However, belts stretch, they wear out, and if you want more precision screws and racks are the way ...

The screw itself wasn’t too hard to ... of “open-face sandwich” approach, creating half-nuts in a single piece of brass using a CNC machine and a ball-nose mill. The threads were completed ...