Equation-based object-oriented (EOO) modeling and simulation techniques have in the last decades gained significant attention both in academia and industry. One of the key properties of EOO languages is modularity, where di↵erent components can be developed independently and then connected together to form a complete acausal model. However, extensive modeling without explicit model validation together with a real physical system can result in incorrect assumptions and false conclusions. In particular, in an educational and research setting, it is vital that students experiment both with equation-based models and the real system that is being modeled. In this work-in-progress paper, we present a physical experimental robotic arm platform that is designed for teaching and research. Similar to EOO models, the robotic arm is modular, meaning that its parts can be reconfigured and composed together in various settings, and used for di↵erent experiments. The platform is completely open source, where electronic schematics, CAD models for 3D printing, controller software, and component specifications are available on GitHub. The vision is to form a community, where new open source components are continuously added, to enable an open and freely available physical experimental platform for EOO languages.