Servos are designed to `compete with steppers`

Panasonic has developed a range of servo motors designed to compete on price with high-end stepper systems but to offer improved performance in terms of their dynamic behaviour, positioning accuracy, torque and power range. The S-Series motors, available in the UK from Lenze, are up to 30% cheaper than Panasonic`s previous generation of servos.

The motors, which come in five sizes with outputs from 50-750W and rated torques from 0.16-2.4Nm, operate at up to 5,000 rpm and have a 2,500-pulse encoder built in as standard.

They have two modes of operation: a pulse-following mode which emulates the performance of a stepper motor but gives the dynamic response of a servo; and a speed mode, that uses four internal jog speeds set via digital inputs. An encoder emulation output allows full closed-loop control.

Rotor inertia is claimed to be up to 54% lower than those of steppers and the motors have a 400Hz bandwidth. They incorporate frequency analysis functions to detect and minimise mechanical resonance and vibrations.

Peter Walker, Lenze`s business development manager for Panasonic products, expects the new servos to appeal to manufacturers of equipment such as packaging and PCB assembly as it will allow them to change from inverter to servo technology. He says that there has been "no compromise in performance" to achieve the lower pricing. A 200W model will cost £400-500.