The YASKAWA SGMXJ-08AUA6SC2 is a compact rotary AC servo motor from Yaskawa’s Sigma-X (Σ-X) SGMXJ family, engineered for low-capacity motion axes that still demand serious responsiveness. In automation, “small servo” does not mean “simple servo.” It often means the opposite: lighter loads, tighter cycle times, and higher expectations for how quickly the axis accelerates, settles, and repeats the same move thousands of times per day without drifting, vibrating, or overheating. The SGMXJ family was specifically positioned for this sweet spot—medium inertia behavior aimed at precise load matching, with rated speed up to 3000 rpm and maximum speed up to 7000 rpm, and a feedback system designed to keep positional accuracy high even when the environment is not ideal.
At the system level, a servo motor is one node in a closed-loop chain: controller → drive → motor → mechanics → feedback. When that chain is healthy, the machine feels “tight”: motion is crisp, stop positions are repeatable, and the axis does not need constant re-tuning as friction, temperature, and load conditions fluctuate. The SGMXJ platform supports that outcome by combining fast speed capability with a control-friendly inertia profile, which helps reduce the common tuning traps in compact machines—overshoot, hunting at standstill, and resonance that appears when the mechanism warms up.
In real applications, SGMXJ-08AUA6SC2 class motors are often used in laser cutting/marking equipment, packaging sub-axes, precision feeders, small indexing tables, electronics assembly fixtures, compact conveyors, and light-duty robotics modules, where the axis must move quickly but still stop exactly where it should. Public listings commonly describe the “08A” output class as 0.75 kW (750 W) and typically associate it with 200 V class servo systems and a 3000 rpm rated speed profile—consistent with the Sigma-X SGMXJ product positioning for low-capacity, high-responsiveness motion.
Key Specifications (Reference Table, Includes Weight)
| Item | Value / Description |
|---|---|
| Brand | YASKAWA |
| Model | SGMXJ-08AUA6SC2 |
| Product Type | Rotary AC Servo Motor (Sigma-X Σ-X, SGMXJ Series) |
| Design Intent | Medium-inertia motor optimized for responsiveness and precise load matching |
| Rated Speed (Series-Level) | Up to 3000 rpm (rated), up to 7000 rpm (max) |
| Rated Torque Capability (Series-Level) | Rated torque up to 8.36 N·m when required (family statement) |
| Feedback / Encoder (Series-Level) | 26-bit absolute encoder resolution (family statement) |
| Output Class (Common Market Reference) | 0.75 kW (750 W) for “08A” class (commonly listed by suppliers) |
| Input Power Supply (Related 08A Frame Reference) | 200 V class (08A product detail example) |
| Product Net Weight | Approx. 2.8 kg |
What makes the SGMXJ-08AUA6SC2 useful in compact automation
1) Speed capability that actually translates into cycle time
A motor that can spin fast is not automatically “faster” in a machine. The real win is how quickly the axis can accelerate, decelerate, and settle without ringing. The SGMXJ line is positioned for responsiveness, which is the combination of speed range, inertia characteristics, and feedback resolution that lets the servo drive close the loop tightly. The official SGMXJ description emphasizes rated speeds to 3000 rpm, 7000 rpm max speed, and the intent to maximize responsiveness for low-capacity applications.
2) High-resolution feedback to reduce “small errors that become big problems”
In high-throughput equipment, tiny repeatability errors accumulate into scrap, rework, and periodic “mystery misalignment.” The SGMXJ family’s 26-bit absolute encoder is a strong signal that the platform is built to maintain positional accuracy and stable motion behavior across operating conditions.
This matters especially in machines where the axis is not rigid—belts, couplings, small gear reducers, and lightweight frames all introduce compliance that can amplify small control errors.
3) Medium inertia behavior that helps tuning stay sane
Many compact machines suffer from one of two extremes:
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Low inertia motor + flexible mechanics → twitchy axis and resonance
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High inertia motor + small load → sluggish response and thermal waste
SGMXJ is described as medium inertia and designed for “precise load matching,” which is exactly the engineering language you want to hear when the goal is stable tuning without sacrificing responsiveness.
Installation and commissioning notes (the stuff that prevents downtime)
Cable routing and grounding decide whether the axis behaves
Servo feedback is sensitive. If feedback/encoder wiring runs parallel to motor power cables, or if shields are terminated inconsistently, you can get intermittent alarms, jitter at low speed, or drift-like behavior that looks mechanical. Keep power and feedback separated, use proper shield termination, and make grounding a deliberate design choice rather than an afterthought.
Mechanical alignment protects bearings and repeatability
A 0.75 kW-class servo can still destroy bearings quickly if the coupling is misaligned or the pulley runout is poor. Misalignment often shows up as heat, noise, and position error that worsens as the system warms up. Treat alignment and coupling selection as part of motion control—not “mechanical housekeeping.”
Size the system by RMS load, not peak torque fantasies
Compact axes often run aggressive motion profiles. The motor might handle the peak torque briefly, but the real limiter is RMS torque and thermal rise over time. If the axis does frequent stop/start and rapid reversals, make sure the drive tuning and motion profile do not force continuous high current that cooks the motor.
Weight (why it matters beyond shipping)
The approximate motor mass of 2.8 kg is useful for more than logistics. It affects:
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Mounting stiffness and resonance (lighter assemblies can shift resonance higher, sometimes into the control bandwidth)
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Robot/end-effector payload calculations
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Vibration behavior of lightweight frames
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Service ergonomics (fast replacement and reduced handling risk)
The best-supported published reference for the SGMXJ-08 frame is ~2.8 kg, supported by an official Yaskawa Europe product detail for the 08A frame and an SGMXJ external-dimensions PDF that references an approximate mass of 2.8 kg.
Summary
The YASKAWA SGMXJ-08AUA6SC2 is a Sigma-X SGMXJ rotary AC servo motor aimed at compact motion axes where responsiveness and repeatability are the real requirements. The SGMXJ platform emphasizes medium inertia, rated speed up to 3000 rpm (7000 rpm max), and a 26-bit absolute encoder to maintain high positional accuracy across operating conditions.
