Fanuc alarm SP0741: RIGID TAP ALARM : EXCESS ERROR

What it means

During rigid tapping, the spindle positional deviation while the spindle was moving exceeded the permitted value, meaning the electronic geared pair formed between the Z axis and the spindle lost synchronization. Load spikes from chip packing, dull taps or an unbalanced tapping condition are the usual triggers. Persistent occurrence at light loads points to a feedback or amplifier problem.

Likely causes

• Tap binding due to chips, coolant starvation or worn tool
• Rigid tap acceleration/deceleration time constants too aggressive
• Deteriorating spindle motor feedback (built-in coder)
• Weak or failing spindle amplifier output stage

Replacement parts

We supply the following units for this alarm — tested, warranty-backed:

• A06B-6120-Hxxx

  alpha i Spindle Amplifier Module (SPM) · Check if others ruled out

  Request a quote →

• A860-2000-T301

  alpha i Motor Sensor (built-in Mi coder) · Check if others ruled out

  View part →