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

Die protection setup - what parameters do you use?

ray_shopfloor

Setting up die protection on our new press. What parameters and sensors do you use? I want to protect the tooling without getting nuisance trips.

**What Is Die Protection
**
Die protection monitors the press stroke and stops the press if an abnormal condition is detected — before the die is damaged. On a servo press, die protection is more effective than on mechanical presses because the press can stop faster.

**Types of Die Protection Sensors
**
**Tonnage monitoring:** Detects abnormal force. Catches double blanks, missing blanks, broken punches.

**Position sensors in die:** Detect material presence, part ejection, scrap removal. Typically inductive proximity sensors or fiber optic sensors.

**Cam switches:** Trigger at specific slide positions to check sensor states.

**Setting Up Position-Based Die Protection
**
1. Define check windows: the slide position range where each sensor should be in a specific state
2. Example: material presence sensor should be ON between 180mm and 10mm above BDC
3. If sensor is OFF during this window: stop press immediately

**Servo Press Stopping Distance**

A servo press can stop in 5-15mm of slide travel (depending on speed and press size). A mechanical press needs 30-60mm. This means die protection is more effective on servo presses — less die damage when a fault is detected.

**Common Die Protection Faults
**
- Part not ejected: part sensor still ON after return stroke
- Scrap not cleared: scrap sensor still ON at start of next stroke
- Double blank: tonnage high limit exceeded
- Missing blank: tonnage low limit not reached

**Parameter Settings**

Set stopping distance parameter to 10mm for most applications. For fragile dies, reduce to 5mm (requires slower forming speed).

toolndye_dave

Die protection saved my most expensive die last month. A slug got stuck on the punch and the press detected the abnormal force signature within 2mm of contact. Stopped before any damage. Without die protection, that slug would have punched through the die steel and caused $25,000 in damage. Setup took 30 minutes. Best 30 minutes I've ever spent.

lisaQ_metrology

The key to good die protection is setting tight windows. Most shops set the force window too wide because they're afraid of false stops. Start tight and widen only if you get false triggers. A false stop costs you 30 seconds. A missed die crash costs you $10,000+. I'd rather have 2 false stops per shift than one die crash per year.

mchen_servo

Tight windows are the right call, but there's a nuance people miss — you need separate windows for the approach phase vs the working phase. We run a 300T doing progressive die work and our die protection has 3 zones:

Zone 1 (approach, 0-5mm before contact): force must stay below 2% of capacity. Anything above that means a slug or misfeed. This is your early warning and it catches 80% of problems before they become expensive.

Zone 2 (working stroke): force window ±12% of the learned curve. We teach the curve over 50 good parts, not 5. Bigger sample smooths out the normal variation from material thickness tolerance and lube distribution.

Zone 3 (strip through): force must drop back below 8% within 3mm after breakthrough. If it doesn't, something is hanging up — slug on the punch face, strip not feeding, pilot pin dragging.

The other thing — if your press supports it, monitor the force curve SHAPE, not just peak force. We had a die wearing unevenly that kept the peak force within window but the curve shape was drifting. The area-under-curve check caught it about 2000 parts before it would have become a quality escape. Saved us a customer complaint on a medical connector job.

One practical tip: label your die protection setups with the die number and date. We store ours as recipes in the press controller. Nothing worse than loading the wrong protection profile after a die change and getting 50 false stops because the windows don't match.