Week13: Moulding and casting

This project involves exploring the processes of moulding and casting through both group and individual assignments. The goal is to design, create, and use moulds to cast parts while adhering to safety protocols and achieving high-quality surface finishes.

Group Assignment

The group assignment focused on gaining an understanding of moulding and casting materials and techniques. Tasks included:

• Reviewing the safety data sheets (SDS) for each moulding and casting material.
• Making and comparing test casts using various materials.
• Comparing the advantages and limitations of printing versus milling moulds.

These activities provided insights into material properties, application techniques, and the importance of choosing the right method for mould creation.

Individual Assignment

In the individual assignment, the objective was to design and fabricate a mould, ensuring it met specific criteria, including smooth surface finish and usability for casting parts.

Designing the Mold

I started by conceptualizing the part to be cast and its intended use. Using CAD software, I designed a mould that would effectively capture the required details. The design process considered the limitations of the chosen moulding process, such as the need for draft angles to facilitate part removal.

The mold design was optimized for either 3D printing or milling, depending on the level of detail and material requirements. For this assignment, I chose to use milling to achieve a high-quality finish and robust mould structure.

Production and Surface Finish

After finalizing the design, I fabricated the mould using a CNC milling machine. The machine settings were carefully selected to ensure precision and a smooth surface finish. Parameters such as spindle speed, feed rate, and cutting depth were optimized based on the material and tool specifications.

Post-processing techniques, including sanding and polishing, were employed to eliminate tool marks and achieve a seamless surface finish that did not reveal the production process.

Using the Mold for Casting

The mould was prepared for casting by applying a release agent to prevent the cast part from sticking. The chosen casting material was thoroughly mixed according to its safety data sheet instructions, ensuring accurate ratios for consistency and strength.

The casting material was poured into the mould carefully to avoid air bubbles. After curing, the cast part was removed and inspected for defects. Minor imperfections were resolved by adjusting the process for subsequent casts.

Learning Outcomes

This assignment provided valuable insights into the moulding and casting process. Key learning outcomes include:

• Designing objects within the limitations of the chosen moulding and casting process.
• Demonstrating workflows for mould design, construction, and casting.
• Understanding the properties of different materials through practical comparison.
• Achieving smooth surface finishes through proper machining and post-processing techniques.

Reflections and Challenges

The assignment highlighted the importance of understanding material properties and process limitations. Reviewing the safety data sheets for each material ensured that the moulding and casting processes were conducted safely. Comparing test casts provided a clear understanding of material suitability for various applications.

Challenges encountered during the assignment included achieving a perfect surface finish and avoiding air bubbles during casting. These issues were addressed through careful process adjustments and attention to detail in preparation and execution.

Documentation

The following resources and artifacts are included as part of the assignment documentation:

• Links to the group assignment page and individual reflection.
• Design files for the mould and detailed descriptions of machine settings.
• Safety data sheets for all materials used.
• A ‘hero shot’ showcasing the mould and final cast object.

Conclusion

This project was a comprehensive exploration of moulding and casting processes, from material selection to final part production. The knowledge and skills gained will be invaluable for future projects requiring custom parts and precise manufacturing techniques.