After the successful completion of the production of the material-optimised concrete façade mullions, Fabio Scotto and Ena Lloret-Frischti of the Gramazio Kohler Research Group at ETH Zurich and the Chair for Physical Chemistry of Building Materials, ETH Zurich take a look back at the experiments and prototypes which were necessary in the development of a final robotic fabrication process. The integration of Smart Dynamic Casting (SDC) for the production of the façade mullions for the first floor of DFAB HOUSE has led us to the development of an adaptive robotic setup which allows us to produce custom-made reinforced concrete structures. Until the final development of a robust robotic process, we had to overcome several challenges during the experimental and prototypical phase. Scaling down the production system and minimizing the friction forces Our first main task was to scale down the production system to realise structures with a minimal cross section of 100 70 mm. This had a direct impact on the formwork system we were working with previously.