Opening Doors for Supercars


Our customer required fixturing and machining of 4 different aluminium castings for a lightweight door opening mechanism for a new supercar. The castings were to be heat treated for increased strength which always introduces a random element into the equation. 


To develop a fixturing and machining strategy, initially for castings of several prototypes and latterly for a five year production contract of cast components. 

The instruction was to design fixtures and manufacturing techniques for long term production for the end user utilizing as few operations as possible to minimise costs whilst maintaining volume and quality consistency. Fixturing castings in CNC machines is an art and science requiring complete understanding of both subjects if costs, operations and times are to be minimised; and low costs was a specific requirement of this project. 

Initial Challenges Faced

Achieving cost targets well below that of the initial quote and that of overseas suppliers. 

Distortion during heat treatment was significant which meant every component had different structures and orientations. 

Really tight programming was required that minimised operations, air time and tool changes.  

Specific Challenges Faced

To meet cycle times the machining of left and right hand components at the same time was necessary to minimise loading and set up times. This created difficulties as different datums on for both components needed to be incorporated in one programme.

Initial prototype fixture presented itself as a feasible option. This later proved to be incorrect due to the twisting and bending stresses of the component during the casting and heat treatment process.

The insertion of Heli coils into a blank hole was time consuming and tricky to perfect every time. 

Solutions Presented

Machining left and right in one operation on a Mazak CV5 500 on a 500mm table size reduced cycle times from 2 hours to 45 minutes in a single operation which included an assembly cell to insert helicoils.

In order to absorb and correct the heat treatment induced distortion a substantial fixture rendition was presented to avoid the twisting action and the holding was made as close to free state as is possible by using a single point profiled upstand with a through clamp mechanism; alleviating the need to counteract the twist in the casting. We were able to utilise Digital Twin simulations to predict likely distortion caused by heat treatment and develop a holding plan using a 3D modelled simulation solution. 

New posting and programme upgrade were required in order to achieve the datum correctness as stipulated by the end user. Tolerances of less that 20 microns were required to ensure the car line of over 3,5 meters could be achieved. A CMM report of up to 98% effectiveness was achieved which proved far better than the customers requirements, reducing their need to manually adjust door fixtures.

A draft angled off centre up stand issue was overcome by a reverse angle interpolation which was developed by us and communicated to our CAM software provider who has since added it to their library.

Carbide form tooling including IMX and adjustable head lollypop cutters designed in house allowed us to reduce cycle time by 20% over standard tooling and programming strategies.

New tooling for Heli coil insert was procured to reduce the manual insertion incorporating POKE YOKE techniques. 


A learning curve for us in relation to the machining of thinly cast components. This project enabled us to improve our fixture design methodology but we managed to come in below budget and on time.

Machine used

Mazak CV5 500

The Mazal CV5 500 is a high-performance (simultaneous) 5-axis machining centre equipped with a powerful, oil-cooled and directly-driven BT40 spindle, a 500mm diameter direct-drive rotary tilting table with a 1000kg maximum table load, a servo-driven ATC, roller LM guideways and integrated thermal compensation.

The machine supplied to NuMachine was also equipped with the Smooth Mazak control, as well as a 15,000rpm spindle and a touch spindle probe and 3D tool probe package.