What can operators do to ensure a straight cut during parting off operations on the lathe?

What can operators do to ensure a straight cut during parting off operations on the lathe?

• A. Lock the carriage
• B. Lock the tailstock
• C. Tighten spindle bearings
• D. Lower cutting speed

Answer: (A)

During parting off, the tool must stay on a fixed line as the workpiece rotates. Locking the carriage prevents any feed or tool-post movement while the cut is being made, so the cutting edge remains on the same centerline and the cut proceeds straight. If the carriage can move, even slightly, cutting forces and tool deflection can cause the tool to wander and produce a taper. Supporting the tailstock helps the workpiece but doesn’t stop the tool from drifting along the bed, and tightening bearings or slowing the speed don’t directly fix the risk of tool movement during the cut. Locking the carriage directly eliminates that movement, ensuring a true, straight cut.

During parting off, the tool must stay on a fixed line as the workpiece rotates. Locking the carriage prevents any feed or tool-post movement while the cut is being made, so the cutting edge remains on the same centerline and the cut proceeds straight. If the carriage can move, even slightly, cutting forces and tool deflection can cause the tool to wander and produce a taper. Supporting the tailstock helps the workpiece but doesn’t stop the tool from drifting along the bed, and tightening bearings or slowing the speed don’t directly fix the risk of tool movement during the cut. Locking the carriage directly eliminates that movement, ensuring a true, straight cut.