Why tiny errors cause big problems

In deep drawing, the smallest deviation can decide whether a cup emerges flawless or destined for scrap. As manufacturers face pressure to increase flexibility and react to changing product and material demands, the precision required during tool setup has become a hidden bottleneck. Traditional deep drawing systems leave the punch with no freedom to self-adjust, which means even slight misalignments can distort wall thickness and compromise quality.

This challenge prompted researchers at the University of Siegen to explore a fundamental question: what actually happens when the punch and die drift out of perfect alignment, and how can tooling be redesigned to cope with it?

Rethinking the deep drawing tool

The study introduces a non-conventional deep drawing tool that avoids the rigid, statically overdetermined behaviour of standard systems. By giving the punch and blank holder limited lateral freedom before closure, the design allows the components to centre themselves during forming. Instead of relying on highly trained staff and time-consuming adjustments, the tool compensates for inaccuracies directly at the forming zone.

What the simulations reveal

Using finite element simulations with DC05 sheet steel, the team modelled how different levels of coaxial misalignment affect thickness distribution. They found that small offsets already introduce measurable variation, while larger misalignments produce pronounced thinning, thickening and shifts in concentricity. Experiments on a laboratory demonstrator confirmed the digital findings, showing that conventional setups amplify errors whereas the new tool concept maintains much more stable geometry.

A step towards more resilient forming

By reducing sensitivity to misalignment, the proposed tool concept shortens setup time, cuts the risk of defective cups and improves robustness during product or material changes. In manufacturing environments where precision meets constant variability, this approach lays the groundwork for more adaptable and resilient forming operations.

Based on “Modelling the effect of misalignment in conventional and non-conventional deep drawing tools for more resilient cup production”, published in Journal of Physics: Conference Series (Vol. 3104, 2025).