Design and development of a 3D-demonstrator for the application of the robust design approaches

June 18, 2026

Robust design aims to develop products whose performance remains insensitive to the unavoidable variations and deviations from manufacturing, wear, and environmental conditions. Its influence is greatest during the conceptual phase, where most design decisions are made, yet empirical investigation of concept robustness at this stage remains limited by the absence of suitable physical test environments. This thesis addresses that gap by developing a modular 3D coin minting demonstrator for the experimental investigation and visualisation of concept robustness. The demonstrator combines a laser-cut wooden frame with 3D-printed components and pyramidal measurement features embedded in the piston, allowing the tilt angle and minting depth of each coin to be extracted using only callipers. A parametric Onshape model realises the sixteen concepts defined by four binary characteristics (connecting rod length, borehole position, guide length, and guide connection) combined with three controlled piston deviations, yielding 48 configurations. The Design Robustness Index (DRI) was applied to all concepts to establish a theoretical ranking, and an experimental campaign of 48 tests provided the corresponding measurements. The results confirm that the demonstrator captures and visualises robustness differences between concepts, with the guide connection emerging as the dominant characteristic and the piston deviations acting non-monotonically depending on the pre-existing bias. The comparison with the DRI revealed important limitations of the metric, motivating refinements that account for designed-in biases and interactions between simultaneous deviations.

Authors in the community:

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  D

  Duarte Valério Ferreira

  ist1100519

Supervisors of this institution:

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  L

  Luís Manuel Mendonça Alves

  ist13976

mechanical-engineering - Mechanical engineering

eng - English

Instituto Superior Técnico