What is a servo press?

A servo press uses servo motors for precise force and position control during forming operations.

How do I calculate servo press tonnage?

Use our free tonnage calculator at servopress.club/tonnage-calculator.html

Overtravel alarm - causes and recovery

paul_setup

Got an overtravel alarm and the press is locked out. What causes this and how do I safely recover?

**Why Overtravel Alarms Occur
**
**Software limit exceeded:**
- Slide height set incorrectly —die shut height taller than expected
- Motion profile programmed with BDC position below software limit
- Operator error during manual jog mode

**Hardware limit switch activated:**
- Physical overtravel switch triggered (backup to software limit)
- Switch wiring fault causing false activation
- Switch target gap out of specification

**Position reference lost:**
- After power loss, press homes to wrong position
- Encoder fault causing position jump

**Recovery Procedure
**
**Do not panic-jog**
After an overtravel alarm, the press may be at or near a mechanical hard stop. Jogging in the wrong direction can cause damage.

**Identify direction of overtravel**
Check the position display. If position shows a value beyond the software limit (e.g., limit is -300mm, position shows -305mm), the slide has gone too far down.

**Enable overtravel recovery mode**
Most presses have an overtravel recovery function:
- Fanuc: hold OT RELEASE button while jogging in the recovery direction
- Siemens: set parameter p2551 (software limit bypass) temporarily
- Yaskawa: use SigmaWin+ to temporarily disable software limits

**Jog to safe position**
Jog slide slowly in the direction away from the overtravel (upward if bottom overtravel). Move until position is within normal range.

**Investigate root cause**
Before resuming production, determine why overtravel occurred. Check:
- Slide height setting vs die shut height
- Motion profile BDC position
- Home position accuracy

**Prevention
**
Set software limits with 5-10mm margin beyond maximum die shut height. Never set limits at the mechanical hard stop.

raj_pm

We had an overtravel alarm last year that turned out to be a failing proximity sensor on the overtravel limit switch. The sensor was reading intermittently, so the press would trip at random points in the stroke. Replaced the sensor for $45 and the problem was gone. Before you dig into the drive parameters, check the physical limit switches first.

carlos_mx

On overtravel recovery: one thing to add —after jogging out of overtravel, always re-run the homing cycle before resuming production. We had a case where the operator jogged out manually and resumed without re-homing. The position reference was off by 0.8mm, which caused a die crash on the next production run.

jim_apps

Overtravel recovery requires patience. After the alarm triggers, do not attempt to jog the press until you understand why it overtravel occurred. Common causes: incorrect motion profile loaded for the current die, counterbalance failure allowing the slide to drop, or a drive fault during the stroke that caused uncontrolled motion. Fix the root cause before clearing the alarm and resuming.

derek_tooling

Overtravel alarms on our Aida fall into three buckets, in order of frequency:

The most common is operator-induced ??somebody bumps the slide jog past the soft limit during setup, or the die cushion was set wrong and the slide hits the lower stop on the return. Resetting the position reference and re-homing usually clears it. If it comes back the same shift, it's not operator error, keep digging.

Second is mechanical ??counterbalance pressure dropped overnight (check the gauge cold first thing in the morning), or the brake is slipping a few degrees after stop and the next cycle's reference is off. We caught a leaking counterbalance solenoid by paint-marking the slide at TDC for a week and watching the mark drift.

Third and worst is encoder/drive ??usually a marginal Drive-CLiQ or encoder cable that throws a position deviation just big enough to trip overtravel rather than a clean encoder fault. The diagnostic clue is the alarm only happens at high speed or after thermal soak. Swapping cable first, encoder second, drive last has been the right order for us.

Whatever bucket it's in, do not just reset and run. Document the position reading at the alarm ??that number narrows the cause faster than anything else.