Introduction
As part of a four-person team, I contributed to designing and manufacturing a PCB mounting assembly. I focused on CNC machining the standoff mounts, applying quality control techniques to maintain tight tolerances, and verifying fitment in the final assembly.
I designed the standoff mounts in SolidWorks, ensuring proper support and alignment for the sheet metal clips. Key constraints included maintaining a precise pocket fit while allowing easy assembly.
Using a CNC mill, we machined the standoff mounts from an aluminum block to achieve the required tolerances. The milling process included precision drilling and pocketing operations to ensure the sheet metal clips would fit flush within the squared pockets.
After machining, we measured critical dimensions using calipers and micrometers to ensure each standoff mount was within ±0.005 inches of tolerance. This quality control step was crucial in maintaining proper fitment for the sheet metal clips and ensuring consistency across all manufactured parts.
The completed standoff mount was polished to remove machining marks, ensuring a smooth finish and precise fit. The final part met all tolerance requirements and was ready for integration into the PCB mounting assembly.
To validate the design, I tested the standoff mounts with 3D-printed clip-on mounts, designed and printed by another group, ensuring they sat flush within the squared pockets. Adjustments to the pocket dimensions allowed for a secure fit, confirming the structural stability of the assembly.
For the final assembly, we integrated all fabricated components from multiple groups for the final assembly to create the complete PCB mounting system. Each machined and 3D-printed part was assembled and inspected to ensure proper fitment, alignment, and structural integrity. The final prototype was presented to our supervisor for validation, demonstrating the success of our collaborative design and manufacturing efforts.
Reflection
This project reinforced the importance of precision machining, tolerance control, and iterative prototyping in mechanical design. Ensuring the standoff mounts fit securely within the squared pockets required multiple CNC machining iterations and careful quality control to maintain tolerances within ±0.005 inches.
One key takeaway was the impact of small dimensional deviations on assembly fitment. Through test fitting and measurement verification, we identified necessary refinements to improve structural stability and ease of assembly.
Moving forward, improvements could focus on optimizing machining efficiency, refining material selection for durability, and further streamlining the assembly process. This experience emphasized the value of hands-on fabrication and precision engineering in real-world applications.