Shaping the future of caravanning with reduced weight: The VARIO X lightweight chassis
With an innovative concept, chassis specialist AL-KO VT is kicking off the new camping season: Thanks to a highly sophisticated design of the frame components, the weight of the VARIO X lightweight chassis has been further reduced by up to 30 percent compared to the previous chassis – with the same high levels of stability and resilience. This increases the available payload and marks the first step towards the mobility of the future.
“The need for action became increasingly clear,” Eckle explains, and his ambition was awakened. “It’s not just my employer, AL-KO VT – I also personally strive to be an innovation leader and help drive the caravanning sector forward. That’s why I dedicated myself intensively to the topic again and, together with the whole team, completely turned existing lightweight construction concepts upside down.”
Volker Eckle, Head of Pre-Development, Vehicle Engineering, and development engineer Maximilian Zimmermann were key players in this new construction. However, when it came to implementation, the two driving forces were supported by an interdisciplinary team made up of experts from different departments, who furthered the project with great dedication and passion.
It wasn’t just during his own camping experiences with caravans and motorhomes, but also when talking with body manufacturers and customers, that Volker Eckle was repeatedly confronted with the important topic of weight and payload.
What would the optimal solution look like if we had to start from scratch?
After the initial idea phase and a feasibility study, the objective became clear: A new lightweight load-bearing structure concept with at least 20 percent less weight compared to the current standard – without sacrificing stiffness, load-bearing capacity or driving safety.
With the motto: “What would the optimal solution be if we had to start from scratch?”, not only conventional designs but also all materials were critically examined. One thing was clear: Alongside noticeable weight reduction, the new concept also had to address the important issue of sustainability and remain in a price range attractive to end customers.
The team set about tackling various fields of action and questions, including:
- Which materials are fundamentally suitable for chassis construction and combine lightness, durability and recyclability?
- What profiles and cross-sections enable such a structure to bear weight?
- How will the product realistically be used in practice? What loads will the individual components have to endure?
- Where have the previous boundaries been, and how can they be shifted?
- Which manufacturing processes are available for the various solutions?
Inspired by nature
Volker Eckle drew his inspiration during the concept phase from nature: “I like being outdoors and, with my idea in mind, I consciously took a closer look at ‘structures’ in the animal and plant world – as these are famously very efficient and robust.”
The use of renewable resources such as wood was also considered – but ultimately, the specialists returned to tried-and-tested steel as the carrier material. As Volker Eckle explains: “Every material has its strengths and weaknesses – and unfortunately, due to its structure, wood isn’t reliable enough for use in the underfloor area.” On the other hand, steel can easily be separated and, unlike other materials, can be efficiently and safely recycled and returned to the materials cycle today.
Interdisciplinary collaboration delivered the solution
With a smile, Maximilian Zimmermann adds: “That’s what makes a good engineer: selecting the best materials for every application and combining them according to the latest state of the art!”
Once the most reliable and high-performing materials had been identified, the teamwork continued: discussions, calculations, simulations, tests, reviews – after every development stage, the cycle repeated. Volker Eckle and Maximilian Zimmermann found the wide range of perspectives and skills contributed by the various participants especially helpful. “The best thing about this project was that there was no ‘old-school departmental thinking’ – every single colleague embraced the interdisciplinary approach,” recalls Zimmermann. “This meant that new solutions were constantly developed through a combination of engineering know-how and practical experience, ultimately leading to the best possible result.”
The result
- Material cut-outs in the steel frame of the chassis create a honeycomb structure, making it significantly lighter than its predecessors while remaining just as durable and able to bear heavy loads.
- At certain points (for example at the transition from the drawbar to the frame), unnecessary material was removed.
- The rear was shortened by 1.5 metres.
- And a great side effect: The design looks fresh and almost a bit futuristic – it’s a shame it’s hidden once the body is in place!
From the initial concept to series production, around three years went by. During this time, half a million test kilometres were completed. Volker Eckle and Maximilian Zimmermann look back fondly: “VARIO X was a huge challenge for us and a truly outstanding project – it could only grow thanks to the combined perspectives and skills of so many different people. We’re thrilled that we were able to launch the chassis on the market together with great colleagues – and this is just the beginning. We will continue on this path and see what the future brings in terms of new drive systems and materials. More ideas are already in the pipeline and just waiting to be implemented!”
