Which component of a mill is supported by the knee and guides the worktable's motion?

The saddle is a crucial component in the milling machine that is supported by the knee. Its primary function is to accommodate the worktable and enable the horizontal and vertical movement necessary for milling operations. When the saddle is moved, it guides the worktable's motion across the machine, allowing for precise positioning of the workpiece relative to the cutting tool. This ability to adjust the position of the worktable is essential for achieving accurate cuts and maintaining the quality of the finished part.

In contrast, while the head is important for holding the spindle and tooling, and the table is where the workpiece is mounted, they do not directly guide the motion of the worktable itself. The base, on the other hand, serves as the foundational support for the entire milling machine but does not interact with the motion of the worktable. Thus, the saddle's role in guiding the table's movement is critical to the overall functioning of the milling machine.