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

Running AHSS on a 400T servo - our experience

lisaQ_metrology

Sharing our experience running AHSS (Advanced High Strength Steel) on a 400T servo press since there's not a lot of real-world info out there.

We run DP780 and DP980 for automotive structural parts. The servo press was essential — we tried DP980 on our mechanical press and the springback variation was unacceptable. Part-to-part consistency was all over the place.

On the servo, the key was the dwell at BDC. Even 30ms of hold under load reduces springback variation significantly. We also slow the forming speed to about 60mm/s for DP980 — faster than that and we get edge cracking on tight radii.

Die wear is the ongoing challenge. D2 tool steel lasts maybe 80K hits on DP980 before we need to sharpen. We're experimenting with DC53 and PVD coatings to extend that. Anyone else running AHSS and found a good die material solution?

sarahJ_mfg

Similar experience at our plant. We converted a door inner panel line 2 years ago. Scrap went from 4.2% to 1.8%. The biggest factor wasn't the press itself —it was the force monitoring catching bad parts before they got to the next station. On the mechanical press we relied on visual inspection which missed about 30% of defects.

pete_retro

I did the retrofit on a similar line —500T mechanical to servo. The part that surprised everyone was the noise reduction. We went from mandatory hearing protection to normal conversation levels at the press. Operator satisfaction went through the roof. It's not in the ROI spreadsheet but it matters.

mchen_servo

The noise reduction point is real and underrated. We had the same experience on our 300T conversion. What I'd add ??the vibration reduction matters just as much as noise. On the mechanical press we had a fatigue crack develop in the die shoe after about 18 months. On the servo we're at 3 years with no cracks. The snap-through shock on a mechanical press is brutal on tooling.

One thing we didn't anticipate with AHSS: the springback variation between coil lots. Even with the same grade and thickness, different coils have slightly different yield strength. On the mechanical press this just showed up as scrap. On the servo we programmed a quick springback compensation routine ??measure the first 3 parts of each new coil, adjust the overbend angle automatically. Scrap on coil changeover dropped from about 12 parts to 2.