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

We cut energy costs 30% on our servo press - here's how

don_tooling

We replaced a 200T mechanical press with a servo last year and I finally have 12 months of energy data to compare. Figured I'd share since I couldn't find real numbers when I was making the purchase decision.

Short version: our electricity cost for that press dropped about 30%. The mechanical was drawing 45kW average during production. The servo averages 31kW running the same parts at the same SPM. Idle draw is where the big difference is — mechanical was 18kW idling (flywheel), servo is about 2kW.

The 30% savings works out to about $8,400/year at our electric rate. Not life-changing but it adds up. The bigger savings came from power factor correction — the servo has near-unity PF so we stopped getting hit with the utility penalty. That was another $400/month we didn't expect.

Anyone else tracked their actual energy savings? Curious if 30% is typical or if we're on the high/low end.

carlos_mx

We measured before and after on our 400T line: 42% energy reduction after optimizing motion profiles and enabling regeneration. The biggest single gain was reducing idle power —the mechanical presses drew 65 kW at idle, the servos draw 3 kW. Over a year with our coil change frequency, that alone saved $18,000.

anna_plc

Regenerative braking setup is where most shops leave money on the table. The default drive parameters are usually conservative. On Siemens S120, adjusting the regen power limit (P1243) from default 50% to 80% increased our energy recovery by about 25%. Just make sure your braking resistor can handle the extra load if regen fails.

mchen_servo

Nice writeup. The regen parameter tuning is a good call — we did the same on our Yaskawa drives (Pn600 series regen settings) and picked up about 20% more recovery.

One thing I'd add that nobody talks about: power factor correction. Our servo press line was running at 0.72 PF before we added capacitor banks. The utility was charging us a PF penalty of about $400/month. $6,500 install for the correction unit, paid for itself in 16 months. Not technically "energy savings" but it hits the same line on the budget.

Also worth checking — a lot of shops leave the cooling fans running at 100% all the time. Most modern drives support temperature-controlled fan speed. On our S120 drives we enabled the auto-fan feature (P0206=1) and the fans now run at maybe 40% most of the time. Doesn't sound like much but across 6 drives that's about 800W continuous savings, plus the fans last 3x longer so you're not replacing them every 2 years.

The idle power thing is huge though. We measured 4.2 kW idle on our 300T with drives enabled. Added a PLC timer — if no cycle command for 3 minutes, it drops the drives to standby (0.3 kW). Wake-up takes about 1.5 seconds so operators don't even notice on manual jobs.