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

90-day PM inspection - what's on your list?

vince_tooldie

Putting together a 90-day PM inspection checklist for our servo presses. What's on your list that might not be on mine?

**Mechanical Systems
**
**Slide and Gibs
** Measure gib clearance with feeler gauges at top, middle, and bottom of travel. Acceptable clearance: 0.02-0.05mm. Clearance over 0.1mm: adjust gibs. Clearance over 0.2mm: inspect for wear.

**Eccentric Bearings
** Check oil level in gear housing. Take oil sample for analysis. Listen for bearing noise during slow-speed jogging. Check bearing temperature with IR thermometer, normal is under 70C above ambient.

#**Counterbalance System**
Check air pressure, typically 0.3-0.6 MPa. Inspect air cylinder seals for leaks.

**Electrical Systems
**
#**Servo Drive Cabinet**
Clean cooling fans and heat sink fins. Check all terminal connections for tightness. Inspect DC bus capacitors for bulging or leakage.

**Motor and Feedback
** Check motor mounting bolts. Inspect encoder cable for chafing at flex points. Check motor insulation resistance, should be over 100 megaohm at 500V DC.

#**Safety Systems**
Test all E-stop buttons, verify response time under 200ms. Test light curtain function. Verify brake engagement time under 50ms.

**Documentation
**
Record every measurement, not just pass/fail. Trending is more valuable than single readings. A press that gives you 3 months of warning is a well-maintained machine.

raj_pm

Good checklist. I'd add counterbalance pressure check to the daily list. It takes 30 seconds to glance at the gauge and it prevents the most common cause of servo motor overload on the return stroke. We had a slow leak that dropped pressure 15% over a month —motor was working 15% harder than it should have been.

pressroom_tom

As the guy who does these checks every day: make the checklist SHORT and put it on a laminated card at the press. If it's a 3-page document in a binder, nobody reads it. Our daily check is 8 items, takes 3 minutes. Anything more and operators start skipping items.

mchen_servo

Laminated card at the press — 100% agree. Our daily is 6 items and even that's a fight sometimes.

For the 90-day list specifically, here's what most people miss:

1. Brake engagement time test. Put a dial indicator on the slide, trigger an E-stop at slow speed, measure how far the slide travels after the stop signal. Compare to your baseline from commissioning. If it's grown by more than 15%, the brake disc is glazing or the spring pack is weakening. This is a safety item, not optional.

2. Encoder cable flex test. Wiggle the cable at the connector and at every flex point while watching the position display. Any flicker or jump means the shielding is cracking internally. We had an intermittent position fault that only showed up at high speed — turned out the cable had a hairline break that only opened under vibration. $85 cable vs $4,000 in scrap parts before we found it.

3. Cooling system flow rate. Not just "is the chiller running" but actually measure GPM at the motor and drive cabinet. Scale buildup in the lines reduces flow gradually. We check with a simple bucket-and-stopwatch method at the return line. If flow drops below 80% of spec, flush the lines with descaler.

4. Ball screw backlash (if applicable). Indicator on the slide, push up and down by hand with drives disabled. Should be under 0.01mm on a newer press. If it's over 0.03mm you're losing position accuracy and your parts will show it before the press alarms on it.