18mm snap-off utility knife

A simple utility knife compatible with ubiquitous 18mm snap-off blades.
As one would expect, the slider "clicks" every 0.5cm (blade snaps every 1cm) and can be fixed not to move.

The design comes in two versions: thin (4mm) and thick (6mm). I designed the thin one first, and decided that it's too thin, so I changed the design to be slightly thicker.

The main body of the knife has two parts that interlock together by slanted insets in adjacent walls.

The pin in the slider (that fits in the mounting hole of the blade) is separate, so that the model needs no supports when printing.