Work may be thrown out of the lathe if which condition occurs?

Work may be thrown out of the lathe if which condition occurs?

• A. The dead center burns off
• B. The spindle speeds too high
• C. The feed rate is too slow
• D. The tailstock is too far away

Answer: (A)

When a workpiece is supported between centers, the tailstock center bears the end of the work and keeps it aligned along the spindle axis. If the dead center burns off, its point becomes damaged or softened, which drastically reduces its ability to grip and support the work. The contact becomes erratic, lubrication fails, and the work can lose control and be expelled from the machine as the spindle still turns. Keeping the dead center sharp, properly lubricated, and well seated is essential for maintaining safe, controlled turning. The other scenarios may cause problems—too high a speed can overheat or chatter, a very slow feed affects surface finish, and the tailstock being too far away reduces support—but they don’t directly create the sudden loss of grip that a burnt dead center does, which is what leads to the work being thrown.

When a workpiece is supported between centers, the tailstock center bears the end of the work and keeps it aligned along the spindle axis. If the dead center burns off, its point becomes damaged or softened, which drastically reduces its ability to grip and support the work. The contact becomes erratic, lubrication fails, and the work can lose control and be expelled from the machine as the spindle still turns. Keeping the dead center sharp, properly lubricated, and well seated is essential for maintaining safe, controlled turning.

The other scenarios may cause problems—too high a speed can overheat or chatter, a very slow feed affects surface finish, and the tailstock being too far away reduces support—but they don’t directly create the sudden loss of grip that a burnt dead center does, which is what leads to the work being thrown.