My mum loves to knit and crochet and there is yarn all over the house. We agreed that some type of organization is needed. I have found some yarn bobbins on thingiverse, but I wanted to make them in different sizes and modify the shape of the bobbin.

My yarn bobbins come in 3 sizes:

Small(S)
Dimension: 7 x 7 x 0.3 cm
Width of yarn catcher: 1 mm

Medium(M)
Dimension: 10 x 10 x 0.4 cm
Width of yarn catcher: 2 mm

Large(L)
Dimension: 13 x 13 x 0.5 cm
Width of yarn catcher: 3 mm

On each bobbin there are 2 yarn catchers. The longer one (that goes closer to the center of the bobbin) is used for starting a ball of yarn. After you have finished winding, you can use the second yarn catcher to secure it. If needed, any of the 4 corners can be used to wrap the yarn around and tie the knot.