A milestone for Mitter: how we delivered the Ford Explorer electric window regulator project
Manufacturing the FORD CX470 family of components is the largest and most complex automotive project in Mitter's history. During more than a year and a half of preparation and manufacturing, we not only tackled technical challenges but also introduced numerous new technologies, machines and capabilities. The project became a milestone: it included the largest tool we had ever built, triggered major investment for series production and, last but not least, became our first large-scale robotised production operation.
The starting point: high expectations and high stakes
From the outset, we knew this would be no ordinary task. Customer requirements were extremely strict, and tolerance limits were often difficult to meet. Even during prototyping, extensive consultation was needed: we worked with the customer to fine-tune critical dimensions and measurement methods.
The project's complexity and scale are also reflected in our use of external designers for two of the three tools and subcontractors for several stages of series-tool manufacture. This allowed us to meet the deadline while continuing to serve our other customers without disruption.
This required flexible yet exceptionally intensive teamwork.
Our engineers described these tools as a textbook collection of technical challenges
Three tools were made for series production, for three different products:
- two 2-cavity tools for the larger components,
- one 4-cavity tool for the smaller but exceptionally complex component, which became the largest tool in Mitter's history, <span style="font-weight: bold; font-family: Calibri; font-size: 11.0pt;">weighing 4800 kg.
All three tools use valve-gated hot-runner systems because they process long-glass-fibre-reinforced PP. Injection moulding simulations at the start of the project confirmed that only sequential valve gating could achieve optimum filling and acceptable weld-line quality.
Our engineers consider these tools a textbook collection of technical challenges:
- mechanical slides,
- hydraulically operated core pins,
- insert-holding elements,
- a complex, segmented cooling system.
The cooling system of the 4-cavity tool is so complex that the cooling pipework requires the system to be dismantled before every tool change – a separate operation in itself. Due to its size, the tool only just fits between the tie bars of our new Demag 650 machine.
Investment: a new machine, a new crane and new capabilities
Significant investment was needed to deliver the project.
- We purchased a Demag 650 electric injection moulding machine with a special screw capable of processing long-glass-fibre material with minimal damage.
- To move the enormous tools, we built a new crane runway and commissioned a new crane.
- We installed a Sepro robot and several temperature control units for precise temperature control.
This project was our first substantially robotised production process, bringing new knowledge and a new approach to our daily work.
Series production: from the first delivery to stable operations
The first actual series delivery took place in May 2024.
Naturally, not everything went smoothly when production started:
- fine-tuning the robots took time, so the initial scrap rate was higher than expected,
- a total of 902 measurement points had to be managed across the three products, which was an enormous task,
- measurement fixtures and programmes were developed and refined in close cooperation with the customer, with weekly online meetings and monthly face-to-face discussions.
Overall, we achieved an average cycle-time improvement of 10% across all three products compared with the start of production. It is important to note that this did not involve exceeding technological limits: the robot's initial safety settings had made the actual starting cycle time longer than calculated. Once we fine-tuned the robot using production experience, we achieved the cycle time committed to in our quotation.
After the initial difficulties, production gradually stabilised and now runs smoothly and according to plan.
Lessons learned
The CX470 project led to considerable internal development:
- A brand-new electric injection moulding machine and expanded infrastructure,
- The introduction of complex robotised production,
- Stronger engineering and quality assurance capabilities,
- Experience of working with external specialists.
For the team, this was a personal challenge as well as a professional one.
As one colleague put it: “It was both a major challenge and an inspiring task.” Another added: “We have never had so many customer meetings on a single project.”
From milestone to springboard
As a result, the project successfully entered series production and continues to run reliably at a high level of quality. Alongside customer satisfaction, it also contributed to Mitter's internal development: we gained knowledge and capabilities that will benefit major future projects.
The CX470 project was a milestone for Mitter: it demonstrated our ability to solve the most complex automotive challenges. The knowledge and experience gained provide a solid foundation for taking on complex projects with even greater confidence in the future.
