8552

Common Causes

• Tailstock chuck clamp commanded during spindle rotation while the spindle chuck was still clamped
• Tailstock mode switch moved to AUTO with the tailstock neither retracted-with-chuck-unclamped nor advanced-with-chuck-clamped
• Tailstock advance/retract or chuck clamp/unclamp confirmation signals not matching the actual position
• Mode switch or confirmation input wiring fault giving a false state

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code 1 = Tailstock chuck clamp commanded during spindle rotation while the spindle chuck was not unclamped; code 2 = Tailstock mode switch set to AUTO while tailstock/chuck were neither retracted-and-unclamped nor advanced-and-clamped
2. 2Read the alarm code: 1 = clamp command during spindle rotation with spindle chuck clamped; 2 = mode switch set to AUTO in an invalid tailstock/chuck state.
3. 3Code 1: stop the spindle and unclamp the spindle chuck before commanding the tailstock chuck clamp; never attempt the transfer clamp while the workpiece is still held and turning.
4. 4Code 2: jog the tailstock to a defined end state — either fully retracted with the chuck unclamped, or fully advanced with the chuck clamped — then switch the tailstock mode to AUTO.
5. 5If the tailstock and chuck are physically in a valid state but the alarm persists, check the tailstock advance/retract and chuck clamp/unclamp confirmation switches and their connectors for a signal that does not match the actual position.
6. 6If it returns after these checks, record the alarm number, code and object and contact Okuma service.