McLaren Tech Club - Episode 21 - How to build a carbon fibre monocoque

Summary

McLaren's Composite Technology Centre in Sheffield produces the next-generation carbon fiber monocells for their vehicles. Using dry fiber material and advanced automated techniques, the facility manufactures lightweight and high-performance chassis. The process involves multiple stages, including precise cutting, forming, and resin transfer molding. With over 40 years of expertise, McLaren engineers design both the chassis and the manufacturing processes. The final product undergoes stringent quality checks to ensure accuracy and durability, contributing to the innovative design and performance of McLaren vehicles.

Takeaways

• 😀 McLaren's MCTC in Sheffield is a state-of-the-art facility focused on producing the next generation of lightweight carbon fiber monocells for vehicles.
• 😀 Carbon fiber is significantly lighter than materials like aluminum (45% lighter) and steel (80% lighter), enabling the creation of lightweight structures.
• 😀 The monocell structure is made from a single, integrated piece, unlike traditional vehicle components that are often separate.
• 😀 Carbon fiber manufacturing at McLaren uses dry fabric material, which allows for an automated, high-volume production process, compared to more labor-intensive resin pre-impregnated methods.
• 😀 The carbon fiber material starts as a roll of textile, which is then cut into hundreds of individual pieces needed to make a chassis.
• 😀 A single square meter of carbon fiber can weigh as little as 150 grams, about the weight of two sheets of paper.
• 😀 The production process involves layering multiple thin layers of carbon fiber (up to seven layers for a 1mm thickness) to achieve the necessary stiffness and performance.
• 😀 Forming the carbon fiber pieces into a three-dimensional shape combines craftsmanship and technology, guided by a laser alignment system.
• 😀 McLaren engineers designed and developed custom machines in-house to perform the carbon fiber shaping process, with one machine standing over 11 meters tall.
• 😀 The resin transfer molding process combines dry preforms into a three-dimensional structure, which is injected under high pressure (equivalent to the force of 100 double-decker buses).
• 😀 The final steps in manufacturing include CNC machining to add mounting features and quality verification to ensure precision before the monocell is sent to Woking for vehicle assembly.

Q & A

What is the purpose of the McLaren Composites Technology Centre (MCTC)?

The MCTC is a state-of-the-art facility developed to produce the next generation of monocells or chassis for new McLaren vehicles.

Why does McLaren use carbon fiber for vehicle chassis manufacturing?

Carbon fiber is used because it is significantly lighter than other materials—45% lighter than aluminum and 80% lighter than steel, which helps produce lightweight structures.

What is a monocell in the context of McLaren vehicles?

A monocell is a special, one-piece chassis structure that integrates various components into a single unit, enhancing the vehicle’s architecture and performance.

How does McLaren ensure precision in cutting carbon fiber material for the chassis?

McLaren uses computer-aided engineering combined with 39 years of experience to design the cutting patterns for carbon fiber, ensuring precise and efficient manufacturing of individual pieces.

What is the significance of dry fabric material in the manufacturing process?

Dry fabric material is key to McLaren’s more automated process for carbon fiber manufacturing, allowing for higher volume production with less labor-intensive methods compared to resin pre-impregnated fibers.

How thin is the carbon fiber material used in McLaren chassis, and how is stiffness achieved?

A 1-meter squared section of carbon fiber weighs as little as 150 grams. To achieve the desired stiffness and performance, McLaren layers multiple thin elements of carbon fiber, with up to seven layers required to achieve 1 millimeter of thickness.

What role does skill and technology play in the carbon fiber chassis formation process?

The formation process blends craftsmanship and technology. Skilled workers use laser-guided systems to lay individual pieces of carbon fiber in a precise orientation, ensuring the necessary accuracy.

Can you explain the resin transfer molding process used in the monocell manufacturing?

In the resin transfer molding process, dry preforms are arranged in a 3D shape, loaded into an injection molding tool, and clamped under significant pressure. Resin is injected to create a single-piece monocell, which is then extracted by a robot after the molding is complete.

What is the purpose of the CNC machining center in the final stages of the manufacturing process?

The CNC machining center adds holes, mounting locations, and other features to the carbon fiber chassis. It also machines aluminum inserts within the composite material to ensure precise final product specifications.

How does McLaren ensure the quality of each carbon fiber chassis?

McLaren uses a CMM (Coordinate Measuring Machine) to verify the accuracy of all features on the chassis before it is shipped to Woking to become the foundation for a customer’s new vehicle.