When designing parts that need to be assembled together, it is essential to incorporate a certain tolerance to ensure a proper fit. In some cases, the absence of this design tolerance can result in the two parts being unable to combine at all. To address this issue and facilitate easy installation, we typically reduce the size of one of the parts at the point of combination by approximately 0.1mm. This adjustment helps to create the necessary clearance, allowing the parts to fit together smoothly and securely. By implementing this small modification, we can prevent assembly issues and ensure that the combined products function as intended.