Hardware is the foundation of many scientific disciplines. In fact, access to hardware can be the limiting factor for the speed and quality of research. Innovations related to low-cost and open source practices create tools that accelerate and democratize science. Open source tools promise additional benefits, for example enabling customization and making it easier to fix broken devices, including by manufacturing replacement parts. 

Realizing the goals of low-cost and open source hardware requires attention to how these tools can scale. One type of scale happens through production, when more tools are designed, manufactured, and used. A second type of scale happens when the enhanced availability of tools enables new and more diverse audiences to contribute to science. 

Low-cost and open source hardware challenges traditional product development processes, and thus requires different approaches to enable scale. In order to understand how low-cost and open source hardware scales, traditional innovation and product development processes are compared to low-cost and open source approaches. This white paper then unpacks scale from both the participation and production perspective, with the goal of elucidating recommendations for accelerating scale of low-cost and open source hardware.