Straddle milling setup in manufacturing In a milling operation, two side milling cutters are mounted on the same arbor with a fixed spacer so that the two opposite sides of a workpiece are machined simultaneously in one pass. What is this setup called in conventional machine shop practice?

Introduction / Context:
Straddle milling is a classic production setup used to machine two parallel faces at a controlled spacing in a single pass. It is widely applied for keys, hexes, and flats on shafts where parallelism and size control between faces are important.

Given Data / Assumptions:

• Two side milling cutters are mounted on the same arbor.
• A rigid spacer sets the distance between cutters.
• Both faces of the workpiece are milled at once.
• Conventional horizontal milling machine arrangement is assumed.

Concept / Approach:
When multiple cutters share an arbor to work on one or more faces, the name of the setup depends on cutter arrangement and task. Straddle milling specifically refers to two side cutters straddling the work to simultaneously generate two faces. Gang milling uses multiple cutters to perform different operations in one pass, but not necessarily straddling opposite sides.

Step-by-Step Solution:
Identify the cutters: two side milling cutters on the same arbor.Identify the goal: mill both opposite sides simultaneously.Match terminology: this is termed “straddle milling.”Differentiate from “gang milling,” which is multiple cutters for varied features, not necessarily opposite faces.

Verification / Alternative check:
Standard machining texts illustrate straddle milling with two side-and-face cutters spaced to the required width; gauge blocks or ground spacers ensure accuracy.

Why Other Options Are Wrong:
Side milling is a single side operation. Gang milling is multiple cutters for multiple features, not specifically straddling. “String milling” is not standard nomenclature. Slab milling uses a wide plain cutter for large surfaces, not paired side cutters.

Common Pitfalls:
Confusing gang milling with straddle milling; neglecting proper spacers and arbor rigidity leading to taper or chatter.

Final Answer:
Straddle milling