My cord stopper with a bolt (thread) that stopped the cord. I made two sizes cord stopper - thread diameters - resp. D10 and D14. The D14 has two variants for use - one hole and two holes, by using the same size bolt. You don't need to buy any springs and most important is that it fixes the cord very strong.

Printer: Bambulab X1C

Filament: PLA (GD Filament), 2-3 walls, 15% infill, no support is needed, layer height 0.16. You can use ABS or PETG as well.