Forged Carbon Revisited: Mould Design & Strength Optimisation

Introduction

In this tutorial, we will explore the process of designing and optimizing moulds for forged carbon fibre components. This guide is based on techniques discussed in the Easy Composites Ltd video and will cover everything from CAD design to finishing the final parts. By following these steps, you can enhance the strength and quality of your forged carbon fibre products.

Step 1: Design the Moulds

• Choose the Component: Start by determining the component you want to create, such as a drone arm or linkage.
• Use CAD Software: Utilize CAD software to design your moulds. Ensure that your design includes:
  • Appropriate dimensions for the component.
  • Features that facilitate easy demoulding.
• Best Practices:
  • Use fillets and radii to avoid sharp corners, which can weaken the mould.
  • Consider the flow of resin and placement of vents in your design.

Step 2: 3D Print the Moulds

• Selecting a Printer: Choose a 3D printer capable of producing high-quality moulds. Consider using a printer with a suitable resolution for intricate designs.
• Print Settings: Adjust your settings for optimal results, focusing on:
  • Layer height
  • Infill percentage
  • Print speed
• Post-Processing: Once printed, remove any supports and sand the mould surfaces for a smooth finish.

Step 3: Prepare the Moulds

• Cleaning: Thoroughly clean the moulds to remove any dust or debris.
• Release Agent: Apply a release agent to the mould surfaces to prevent the forged carbon from sticking.

Step 4: Fibre and Resin Preparation

• Fibre Selection: Choose the appropriate type of carbon fibre. For enhanced strength, consider using long-strand unidirectional carbon fibre combined with chopped tow reinforcement.
• Cutting the Fibre: Cut the fibres to the required lengths based on your mould design.
• Resin Mixing: Prepare the resin according to the manufacturer's instructions. Ensure it is mixed thoroughly to avoid weak spots.

Step 5: Loading the Fibre and Resin

• Layering: Place the cut fibres into the mould, ensuring an even distribution.
• Infusing the Resin: Pour or inject the resin into the mould, ensuring it saturates all fibres.
• Avoiding Air Pockets: Use a roller or brush to help eliminate air pockets within the resin.

Step 6: Mould Compression

• Applying Pressure: Close the mould and apply compression using a suitable pressing method. This step is crucial for ensuring optimal fibre alignment and strength.
• Monitoring: Keep an eye on the pressure applied to ensure it remains consistent throughout the curing process.

Step 7: Demoulding the Parts

• Cure Time: Allow the components to cure as per the resin specifications before attempting to demould.
• Careful Removal: Gently remove the parts from the mould, taking care not to damage the newly formed components.

Step 8: Finishing the Parts

• Trimming: Trim any excess material from the edges of the components.
• Sanding and Polishing: Sand the surfaces to achieve a smooth finish and polish if necessary to improve aesthetics.

Step 9: Strength Testing

• Testing Methods: Perform strength tests to evaluate the integrity of the forged carbon parts. Common methods include:
  • Flexural testing
  • Tensile testing
• Analysis: Analyze the results to determine if any design adjustments are needed for future components.

Conclusion

This tutorial outlines the essential steps for designing and optimizing forged carbon fibre moulds. By following these guidelines, you can create durable and high-quality components. Experiment with different designs and materials to further enhance your results, and consider conducting strength tests to continuously improve your processes. For more resources, check out the links provided in the video description. Happy crafting!