The phrase "knocking together" can have a variety of synonyms depending on the context in which it is used. One possible synonym is "assembling," which refers to the act of putting together or bringing together different elements or components to create a larger whole. Another option might be "constructing," which is similar to assembling but often implies a more deliberate and intentional process. Alternatively, "fabricating" can be used to describe the act of creating something from raw materials or components, while "joining" or "connecting" might be used to refer specifically to the physical act of bringing two things together. Finally, "collaborating" or "working together" can be used to describe the process of multiple individuals or groups coming together to achieve a shared goal or purpose.