SIMOTICS S SYNCHRONOUS SERVOMOT 1FK7042-5AF71-1AG0 1FK7 042-5AF71-1AG0 1FK7 0425AF711AGO

Siemens 1FK7042-5AF71-1AG0 | SIMOTICS S 1FK7 Compact Servo Motor — 3 Nm / 0.82 kW / 3000 rpm / Incremental Encoder / IM B5

1FK7 Compact — Servo Performance in a Tight Installation Envelope

The 1FK7042-5AF71-1AG0 is a 1FK7 Compact synchronous servo motor: 3 Nm continuous torque at 3000 rpm in the 48mm shaft height frame. Siemens positions the 1FK7 Compact family for applications where installation space is restricted but full servo performance — precise positioning, repeatable speed regulation, and fast dynamic response — is still required. Feed axes on compact machining centres, indexing mechanisms, packaging machinery, and tightly packaged automation modules are all natural fits.

The permanent-magnet rotor produces consistent torque across the full speed range. Natural cooling (no fan, no external cooling supply) keeps the installation simple — no cooling air connections, no coolant, just the motor surface area dissipating heat by convection. At 0.82 kW continuous, this is appropriate for duty cycles typical of axis feed and positioning applications in compact automation.

Key Specifications

Order Number Decoded — What 1AG0 Tells You

The suffix structure of the order number defines the motor's configuration:

The plain shaft (G0) means no keyway and no holding brake. For vertical axes or gravity-loaded mechanisms, the brake variant (H0 suffix) — same motor with an integral electromagnetic holding brake — is required. The plain shaft relies entirely on servo lock and friction coupling for position holding at rest.

The incremental encoder requires a reference-return cycle at each machine power-up to establish the axis position reference. For absolute position on power-up without homing, a variant with an absolute encoder or EnDat encoder is required.

270° Rotatable Connector — Installation Flexibility

The power and signal connectors on the 1FK7042-5AF71-1AG0 rotate 270° around the motor axis. In a tightly routed cable panel, this means the cable exit direction can be adjusted at installation time — pointing the connector backward, sideward, or at any angle in the 270° arc — without disassembling the cable or modifying the motor. This is a practical advantage in machine builds where cable routing is constrained.

FAQ

Q1: This motor has a plain shaft and no brake. Is it suitable for vertical axes?

No. The plain shaft with no holding brake means position at servo-off depends entirely on servo lock and friction coupling. On vertical or gravity-loaded axes where the load moves under gravity when the servo is de-energised, the brake variant (suffix -1AH0) with an integral electromagnetic holding brake is required.

Q2: Does the incremental encoder require a homing cycle at every power-up?

Yes. The incremental encoder has no absolute position memory — a reference-return cycle is required at each power-up to establish the axis position reference. For absolute position on power-up without homing, specify a 1FK7 variant with an absolute encoder (EnDat) — identifiable by the relevant encoder suffix in the order number.

Q3: What Siemens drives are compatible with the 1FK7042-5AF71-1AG0?

The 1FK7 family is compatible with SINAMICS S120 and S210 servo drive systems, and with SIMODRIVE 611 via the appropriate motor module. Confirm the drive module's rated current covers the motor's 1.95A rated current. When using SINAMICS S120, the drive can connect via DRIVE-CLiQ if the motor is equipped with a DRIVE-CLiQ socket — verify the motor's encoder interface against the drive system.

Q4: What does "IM B5 (IM V1, IM V3)" mounting mean?

IM B5 is a flange mount — the motor mounts via a round flange with a bolt circle on the drive end. The same flange geometry also allows IM V1 (vertical, shaft pointing down) and IM V3 (vertical, shaft pointing up) mounting orientations without a different motor variant.

Q5: Where is the 1FK7042-5AF71-1AG0 sourced given it is discontinued?

Through the Siemens SIMOTICS S aftermarket — industrial servo motor dealers, exchange programs, and refurbishment services. Confirm the full order number 1FK7042-5AF71-1AG0 (encoder type, shaft type, brake/no brake) from the installed motor's nameplate. Encoder condition should be verified on any used unit.