Project 2

Mold Design Report: CPU Fan Bezel

1. Introduction This report details the procedure followed to create a mold for the CPU Fan Bezel model provided in the assignment. The mold was designed considering the shrinkage factor of ABS (0.6%) and best practices in mold design to ensure manufacturability and part quality.

2. Material Considerations

• Material: ABS (Acrylonitrile Butadiene Styrene)
• Shrinkage Factor: 0.6%
• Properties: High impact resistance, good machinability, and moderate heat resistance

3. Mold Design Approach The mold design process followed these key steps:

Step 1: Importing and Analyzing the Model

• The CPU Fan Bezel STEP file was imported into CAD software.
• The part was analyzed for undercuts, draft angles, and critical design features.

Step 2: Scaling for Shrinkage

• The entire model was scaled by 1.006 (to account for the 0.6% shrinkage of ABS).

Step 3: Parting Line and Draft Analysis

• A parting line was determined based on the geometry of the bezel to minimize defects and ensure ease of ejection.
• Draft angles were verified to ensure smooth ejection from the mold.

Step 4: Core and Cavity Design

• The mold was split into core and cavity halves using the parting surface.
• Appropriate clearances and tolerances were considered to prevent defects such as flash.

Step 5: Mold Base Selection

• A standard mold base was chosen based on the size and shape of the CPU Fan Bezel.
• Proper venting and cooling channels were incorporated to optimize cycle time.

Step 6: Runner and Gate Design

• A single-point injection system with a fan gate was used to ensure uniform filling and minimize weld lines.

Step 7: Ejection System

• Ejector pins were strategically placed to prevent warping and damage during part removal.

Step 8: Cooling System Design

• Cooling channels were designed around the critical areas to prevent sink marks and warpage.

Step 9: Mold Assembly and Drafting

• The mold was assembled, and a detailed 2D drawing with necessary dimensions and tolerances was created for manufacturing.

4. Simulation and Validation

• A mold flow analysis was performed to verify material flow, cooling efficiency, and potential defects.
• Adjustments were made based on simulation results to enhance mold performance.

5. Conclusion The mold design for the CPU Fan Bezel was successfully completed, ensuring manufacturability with minimal defects. This project provided hands-on experience in mold design, reinforcing key concepts covered in the course.