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

Yaskawa SGM7J Motor on Servo Press: Parameter Setup and Tuning

admin

## Initial Parameters

Motor parameters (from nameplate):
- Pn170: Rated current (A)
- Pn171: Rated speed (rpm)
- Pn172: Rated torque (Nm)

Position control:
- Pn205/206: Electronic gear ratio
- Pn207: Position loop gain (start at 40)

Safety:
- Pn520: Position deviation alarm (3-5mm in pulses)
- Pn522: Torque limit (300% for press)

## Electronic Gear Ratio Example

SGM7J 23-bit encoder = 8,388,608 pulses/rev
10:1 gearbox, 20mm ball screw pitch, 0.001mm resolution:

Pulses/mm = 1000
Pulses/rev at motor = 20,000 x 10 = 200,000
Ratio = 8,388,608 / 200,000 = 41.94

Set Pn205=4194, Pn206=100

## Tuning for Press

High inertia + variable load = auto-tuning often fails.

Manual procedure:
1. Pn100=50Hz, Pn101=20ms, Pn102=40/s
2. Run 10 strokes at 50% speed
3. If stable, increase Pn100 by 10Hz
4. Stop when oscillation appears, reduce 20%

Typical result for 160T press: Pn100=80-120Hz, Pn102=60-80/s

anna_controls

The electronic gear ratio (Pn205/206) is the most important parameter to get right. It converts encoder pulses to physical distance. Get it wrong and your position commands won't match actual slide movement. Calculate it from: encoder resolution ? gear ratio ? ball screw lead. Double-check by commanding a known distance and measuring with a dial indicator.

jim_applications

For press applications, I always set the position loop gain (Pn102) lower than the default. Presses have high inertia and compliance in the mechanical train. High position gain causes oscillation. Start at 50% of default and increase until you see the first hint of vibration, then back off 20%. That's your sweet spot.