Designing Low-Cost Open-Hardware Electromechanical Scientific Equipment: A Geological Analogue Modeling Sandbox

Scientific experimentation often requires building custom apparatus. However, published results usually focus on the experiment, disregarding technical details of the scientific equipment. Lacking enough information about these custom devices prevents their accurate replication, hindering the experiment reproducibility, which is a fundamental requirement for Open Science. In the field of Geology, custom electromechanical devices with low-speed moving elements are required to analyze scaled-down models of the tectonic deformation processes. In these experiments, the earth crust is modeled with materials whose properties and setup are scrupulously specified to comply with the scale model theory and to have standard and reproducible procedures. Notwithstanding this rigorous characterization, we believe that the moving apparatus has received little attention, implicitly assuming an ideal behavior despite the difficulties of moving uniformly at such slow speeds, which could produce disparities with the natural model. In this paper we address this issue by presenting a device for scientific analogue modeling of contractional and extensional tectonics. We analyze the challenges and implications of moving at such low speeds, demonstrate its satisfactory performance and provide suggestions for improvement. In addition, the proposed apparatus is not only affordable and relatively easy to build, but also is an open-hardware project that can be replicated, improved or customized, even in other research fields. We hope that this contribution will be beneficial for the scientific and educational community, facilitating the reliability of experiments, the exchange of ideas, and thereby the promotion of Open Science.