It has been argued that for any given physics task there is a critical constellation of resources that students need to become proficient in handling in order for physics learning to take place. This is because different resources offer access to different information i.e. they have different pedagogical and disciplinary affordances. A laboratory exercise requiring coordination of multiple resources was designed to help students appreciate the movability of coordinate systems. Initially students were unable to coordinate the manipulation of a hand-held measuring device (IOLab) and observe changes in three readouts on a computer screen, whilst simultaneously drawing conclusions in their discussions with each other and the facilitator. However, the introduction of a paper arrow allowed students to quickly coordinate the resources and begin to experience the movability of coordinate systems. The study confirms earlier work on critical constellations of resources and the functioning of persistent resources as coordinating hubs.