What is the purpose of enlarging the holes common to the -2 and -4 pieces in the assembly?

Enlarging the holes common to the -2 and -4 pieces in an assembly primarily serves to facilitate the insertion of larger fasteners. When parts are designed to accommodate various sizes of hardware, enlarging the holes allows for fasteners that are larger in diameter to be used, which can enhance the strength and structural integrity of the assembly. This modification can also provide a greater margin for alignment during assembly, reducing the risk of misalignment and ensuring that the components fit together correctly.

In addition to this, adjusting hole sizes can aid in the assembly process, especially in instances where the conditions of installation, such as the presence of vibration or thermal expansion, may require robust fastening solutions. Thus, the primary function of enlarging these holes aligns seamlessly with ensuring that appropriately sized fasteners are utilized for optimal performance within the assembly.