New Tech Europe | Jan 2017 | Digital Edition

with the motor which results in a decentralized artchitecture, reducing cabling and simplifying implementation. The stepIM enables the creation of cabinet-less machines. Below we investigate motion-control performance in a woodcutting application, traditionally performed with servos, but now performed with stepIM closed-loop stepper motors. CLOSED-LOOP STEPPERS IN HIGH-PRECISION WOODCUTTING MACHINES A global industrial automation company each year builds and sells hundreds of precision CNC machines to create woodframes for windows. Requiring precise synchronization and high torque, the application required some 20- 30 pneumatic and electronic servo motors in each machine. The cost of the servos added significantly to the overall cost. The high cost of the servos contributed significantly to the overall cost of each machine. Furthermore, the substantial number of additional cables required by the stand-alone, cabinet- mounted servo encoders extended installation time and added to the maintenance complexity. Upon hearing about Servotronix’s stepIM, closed-loop stepper motors, the company was eager to determine their applicability to these wood-processing machines. “Cost has become a big factor in keeping our high-end machines competitive on a global scale,” stated the Head of Development. “However, we could never compromise on performance, precision and reliability.”

Figure 7. StepIM steppers require less current

Figure 8. Centralized vs. decentralized architecture

With open-loop steppers, high momentary torque demands are difficult to achieve due to the risk of losing steps. stepIM closed-loop steppers are capable of very fast accelerations, run more quietly and have lower resonance than conventional stepper motors. They are able to operate at higher bandwidths to deliver superior performance. Decentralized installation stepIMs integrate the electronics

Figure 9. Machine process of wooden window frames

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