What does a machinist use to manually check alignment of the tool tip to the spindle?

What does a machinist use to manually check alignment of the tool tip to the spindle?

• A. Tailstock
• B. Chuck
• C. Carriage
• D. Tool post

Answer: (A)

The tool tip must run on the same axis as the spindle, so you need a reference that is coaxial with that axis. The tailstock provides that reference: it can hold a center or a precisely machined bar aligned with the spindle axis. By bringing a center (or bar) in the tailstock into alignment opposite the spindle center and checking how the tool tip sits relative to that axis (often with a dial indicator or by observing runout as the spindle turns), you can verify and adjust whether the tool tip is truly on centerline. The chuck, carriage, and tool post each have important roles, but they don’t supply the coaxial reference needed to check alignment the way the tailstock does.

The tool tip must run on the same axis as the spindle, so you need a reference that is coaxial with that axis. The tailstock provides that reference: it can hold a center or a precisely machined bar aligned with the spindle axis. By bringing a center (or bar) in the tailstock into alignment opposite the spindle center and checking how the tool tip sits relative to that axis (often with a dial indicator or by observing runout as the spindle turns), you can verify and adjust whether the tool tip is truly on centerline. The chuck, carriage, and tool post each have important roles, but they don’t supply the coaxial reference needed to check alignment the way the tailstock does.