Machines where work rotates and tool is stationary Among the following boring machines, identify the one in which the workpiece rotates on a table while a stationary single-point tool performs the cutting (i.e., tool does not rotate).

Introduction / Context:
Different boring machines achieve relative motion between tool and work in different ways. Recognizing which element rotates is fundamental for selecting setups and tooling.

Given Data / Assumptions:

• Conventional shop machines: vertical and horizontal boring machines, jig borers.
• Stationary tool implies a non-rotating single-point tool taking a cut as the work turns.
• Cutting is analogous to turning operations on a lathe.

Concept / Approach:
In a vertical boring machine (often called a vertical turret lathe), the workpiece is mounted on a large vertical rotary table; the tool is held on a ram or turret and does not rotate. The rotating work under a stationary cutting tool produces the machining action. In horizontal boring, jig boring, and precision boring machines, the tool typically rotates (boring bar or spindle) while the work is stationary or only fed linearly.

Step-by-Step Solution:

Verification / Alternative check:
Machine manuals and training texts depict VTLs with rotating worktables and stationary tools, especially for large diameters.

Why Other Options Are Wrong:
Horizontal boring: rotating boring bar; work is fixed.Precision/jig boring: spindle rotates the tool for accurate holes; work is stationary.CNC drilling: tool rotation is fundamental.

Common Pitfalls:
Confusing vertical boring machines with vertical milling machines; in a VTL the work rotates, not the tool.

Final Answer:

Vertical boring machine (vertical turret lathe type)