3D printable tension meter is a different option for Prusa MK3 and Mini printers, if one has some Prusament PETG to print it in. Everything about belt tension for Prusa printers is covered in ...

For example here is the net of a cuboid. The nets of 3D shapes help you see some of the properties of the shape. This net of a tetrahedron shows you the shape of each face and the number of faces.