Trefoil knot, 90 mm

Description

The trefoil is the simplest non-trivial knot. The curve comes from the parametric equation rather than being drawn by eye, so the section stays constant along its whole length and the crossings read the same from every side.

The section is a 13 mm round. It fits in 84x79x39 mm, which is any bed, mini printers included.

It does need supports: the lowest loop has a stretch of near horizontal overhang. Use tree supports - they peel off a round section cleanly, while normal ones leave scars that show badly on a shape like this.