Simotics S AC Synchronous Servo motor 1FK7042-5AF71-1AG0

1FK7042-5AF71-1AG0 | SIMOTICS S 1FK7 Compact Servo Motor — 3Nm / 0.82kW / 3000RPM / 1.95A / IM B5 / SIN/COS 2048P/R / IP64 / Plain Shaft 

1FK7 Compact — A Servo Motor Designed for Space-Constrained Machines

The 1FK7 Compact series sits between the 1FK7 standard and the 1FT7 high-performance families. Compact means shorter overall length. For the 48mm shaft height frame (1FK7042), this physical constraint matters on machine tools and handling systems where axis spacing is tight and motor mounting depth is limited.

All the servo performance is retained: permanent magnet synchronous construction, smooth torque delivery across the speed range, and predictable dynamic response that a stepper or induction motor cannot match. The shorter body is the trade-off against a slightly lower peak torque capability versus the standard-length 1FK7 at the same frame size.

The 1FK7042-5AF71-1AG0 delivers 3Nm at the rated 100K temperature class — consistent torque across the operating duty cycle without thermal derating concerns under continuous load.

Key Specifications

SIN/COS Incremental Encoder — Analogue Sinusoidal Feedback

The 1FK7042-5AF71-1AG0 carries an incremental SIN/COS encoder (1Vpp, 2048 pulses per revolution). SIN/COS encoders transmit sinusoidal analogue signals rather than digital pulse trains. The drive receives two phase-shifted sine waves and resolves the shaft position by interpolating the signal — extracting sub-pulse position resolution from each sine period.

With 2048 physical periods per revolution, and drive-side interpolation typically adding 256× or more, the effective position resolution is several hundred thousand counts per revolution. For fine positioning, smooth low-speed operation, and precision torque ripple reduction, SIN/COS feedback produces cleaner performance than equivalent-pulse-count digital encoders.

The "-1AG0" designation in the part number confirms this encoder type. Replacement or repair of the 1FK7042-5AF71-1AG0 must use a motor with the same I-2048 encoder variant to maintain drive compatibility without reconfiguring the encoder interface.

Application Scenarios

Machine tool feed axis: A machining centre's X or Y axis drive uses the 1FK7042-5AF71-1AG0 on the ballscrew. The 3Nm torque at 3000RPM covers typical feed axis requirements in small to medium machining centres. Natural cooling is sufficient for intermittent duty feed profiles.

Packaging machine servo axis: Film drive or indexing axis on a horizontal form-fill-seal machine. Compact motor length fits within the tight machine envelope. SIN/COS encoder provides smooth feedback for position-controlled cam profiles.

Replacement on existing SIMOTICS drive system: An installed 1FK7042-5AF71-1AG0 has failed. A direct replacement restores the original torque, speed, and encoder type without modifying the drive parameters — the same part number ensures matching performance and encoder interface.

FAQ

Q1: What servo drives are compatible with the 1FK7042-5AF71-1AG0?

The 1FK7 Compact series with SIN/COS encoder (I-2048) is designed for use with SINAMICS S120 servo drives that support SIN/COS encoder input. The specific drive module selection depends on the required axis current, DC link voltage, and whether a single-axis or multi-axis power module is used. The drive's encoder interface must be configured for the SIN/COS 1Vpp protocol at 2048 pulses/rev.

Q2: Does the absence of a holding brake affect safety for vertical axes?

Yes. A motor without a holding brake cannot mechanically hold a vertical load when the drive is de-energised. For vertical axes (z-axis on machining centres, lifting systems), a holding brake is required to prevent gravity-driven downward movement on power loss. The "-1AG0" configuration has no brake. If the application requires vertical axis load holding, a brake-equipped variant (different suffix) must be specified.

Q3: What does the IP64 protection rating cover?

IP6X means the motor is dust-tight — no dust ingress under any conditions. IPX4 means the motor is protected against splashing water from any direction. Together, IP64 covers machines in typical production environments with coolant splash, dust, and swarf. It does not cover high-pressure washdown (IP65 or above) or continuous immersion.

Q4: What is the 100K temperature class significance for the 3Nm rating?

The "100K" reference means the motor's rated torque of 3Nm is the value at 100 Kelvin temperature rise above ambient — in other words, at a winding temperature of approximately 125°C assuming 25°C ambient. This is the continuous-duty thermal rating. Short-term peak torque will be higher. Operating at lower duty cycles or with active cooling would allow higher sustainable torque; the 3Nm figure is the conservative, continuous-duty specification.

Q5: Is the plain shaft type compatible with couplings requiring a keyway?

A plain shaft (no keyway, no flat) requires couplings or pinions designed for smooth shaft clamping — friction couplings, hydraulic shaft couplings, or press-fit pinions. Couplings designed for keyed shafts cannot be used directly. If the application requires a keyway shaft, a different order configuration suffix must be specified. Confirm shaft type and coupling design compatibility before installation.