Bringing stable torque and high-speed capabilities to the injection robot
One of the primary reasons for utilising servo drives in injection robots is to maintain torque consistency across a wide speed range. Stepper motor drives produce peak torque at low speeds, but this torque is quickly lost as speed increases, limiting cycle time and robot throughput, which can lead to production issues on high-volume moulding lines. In contrast, servo drives maintain nearly constant torque at rated speed, enabling three-axis robot arms to accelerate and decelerate without compromising their strength. This consistent high-speed capability directly translates into faster pick-and-place operations and reduced machine idle time. At the same time, Topstar’s servo injection robots have cycle times that are 20-30% faster than equivalent stepper-driven models. For production results, it can directly improve overall equipment efficiency and handle more complex parts.
Bringing stable torque and high-speed capabilities to the injection robot
More precise positioning can be obtained
Servo-driven injection robots use control systems and communication protocols to achieve accurate closed-loop feedback control. This enables the injection robot controller to continuously compare the actual position with the command trajectory and correct any deviations in real-time. In contrast, stepper-driven robots typically operate in an open-loop mode, assuming that the steps have been successfully executed without verifying the actual movement; this can lead to missed steps, accumulated positioning errors, and part misalignment. Servo robots offer precise control over position, speed, and torque. Handling precision moulds, coordinating synchronous multi-axis motion, or integrating visual-guided part removal can bring a more stable and accurate level of control. By maintaining absolute position integrity, servo injection moulding robots ensure consistent part quality, minimise secondary rework, and support high-precision moulding requirements in the automotive, medical, and electronics industries.
Bringing Dynamic Response and Vibration Suppression to Injection Robot
A dynamic response is required when injection robots quickly start, stop, or change direction between mould opening and closing cycles. Servo drives with advanced control loops and vibration suppression for injection robots can actively suppress mechanical resonances, preventing overshoot or ringing during rapid motion. This results in smoother, jitter-free operation, reduced wear on mechanical components, and position accuracy at accelerations exceeding 5 g. In contrast, stepper drive systems often experience significant oscillations at high speeds due to their inherent step-like motion profiles. Topstar’s range of servo robots demonstrates excellent cycle stability at high accelerations, extending actuator life by 30% and reducing maintenance intervals. This smooth, dynamic behaviour also protects delicate, moulded parts from mechanical shock.
Improving Energy Efficiency and Regenerative Braking for Injection Robot
Energy efficiency is another area where servo drives excel in industrial robots. Many servos utilise a common DC bus and regenerative braking to capture kinetic energy during deceleration and feed it back into the facility grid or shaft, rather than dissipating it as heat. This regeneration capability can reduce overall drive energy consumption by up to 20%, equating to significant energy savings over thousands of daily cycles. In contrast, stepper motors consume constant current to maintain torque even when idling and lack regeneration, resulting in higher continuous energy consumption and increased heat generation in the control cabinet. Additionally, servo drives can achieve more precise torque control, thereby eliminating energy waste during low-load motion. The energy-saving advantages of servo injection robots can significantly lower operating expenses and reduce environmental impact.
Seamless integration and control flexibility
Modern injection moulding production lines require the seamless integration of injection robots with the control system of the injection moulding machine, as well as with the enterprise-level MES system. Servo drives offer advanced motion control functions, including electronic cams, multi-axis interpolation, and automatic tuning, which simplify programming and reduce the need for external motion controllers. The servo-driven injection robots equipped by Topstar can perform complex pick-and-place trajectories, undercutting movements, and synchronised mould opening links with millisecond precision. Integrating communication protocols such as Modbus RTU facilitates real-time data exchange, remote diagnostics, and firmware updates. Stepper motor-based systems often lack many advanced features and typically require additional hardware or software synchronisation. Topstar’s 3-axis robot solution utilises servo drives to provide a flexible and scalable automation architecture that can quickly adapt to changes in mould and product mixes.