This paper presents our investigation in designing a hub and strut kit that interfaces to a 3D graphics application. FlexM is a prototype in progress of a flexible physical interface for manipulating and building 3D geometry. Using the FlexM hub and strut components, designers can build and explore 3D geometry with the ease of a toy and the power of a computer. The hubs transmit the model’s topology and geometry to the computer, where the model is rendered on the screen in real time.