In applications such as optical system alignment, laser scanning, semiconductor inspection, and precise part indexing, open-loop stepper rotary tables often experience step loss, cumulative errors, and long-term wear, leading to positioning drift and making it difficult to guarantee angle accuracy. The Sefan Optoelectronics 7SRA5100B closed-loop electric rotary table, with a built-in high-precision grating disc for real-time feedback, offers a closed-loop controllable and reliable solution with a **±3 arc-second repeat positioning accuracy**, a 20mm hollow through-hole, and a 50kg large load capacity, providing precise rotational positioning for precision applications.
The core upgrade of 7SRA5100B lies in full closed-loop position control. The table is equipped with a high-precision grating disc and reading head, which detect the actual angle position while the motor rotates, forming a "command - execution - feedback - compensation" closed-loop control, completely eliminating step loss, step angle accumulation errors, and positioning deviations caused by load changes. The repeat positioning accuracy reaches **±3″ (arc seconds)**, and after error compensation, the absolute positioning accuracy can reach 10″, with a resolution of 0.00125° in 8 subdivisions. It meets the requirements for precise angle adjustment in optical alignment, precise indexing, etc. The reading head supports digital and analog signal selection, and a higher precision version can be customized.
The transmission system uses precision-finished worm gear pairs, with a transmission ratio of 180:1. It undergoes quenching, fine grinding, and pre-pressing for backlash elimination treatment, resulting in small backlash and smooth transmission. The cross cylindrical roller bearing support structure ensures that the end jump of the table surface is only 0.04mm, and the coaxiality tolerance of the table hole is 0.04mm. During rotation, the radial jump is small and there is no jitter. What's more, the gap adjustment design is ingenious - after long-term use and wear, only a simple adjustment is needed to eliminate the backlash and maintain long-term accuracy, extending the equipment's service life. The bearing structure supports various installation postures such as horizontal, vertical, and inverted, suitable for different optical path layouts and equipment integration directions.
The body is made of high-strength aluminum alloy, with the table surface being black oxide treatment. The table diameter is 100mm, and the center hole is 20mm + 0.025mm, facilitating the passage of optical paths, the passage of cables, or the installation of workpiece shafts. It is particularly suitable for scenarios where optical systems require central light transmission. The table surface has 12 M6 installation screw holes, and the base is reserved for standard installation holes, compatible with optical platforms and equipment racks. The maximum center load is 50kg, while the overall weight is only 2kg. The high rigidity body combines compactness and load-bearing capacity.
The standard configuration includes 42 series two-phase stepper motors, with a maximum static torque of 0.4N·m, a rated current of 1.7A, and a maximum speed of 25°/s (2 subdivisions). It comes with a zero position switch and supports power-on return to the origin. It uses an RS232 (DB9) communication interface and is compatible with Sefan 7SC series motion controllers, supporting 360° continuous rotation, point positioning, speed control, multi-axis linkage, and can be reprogrammed to connect to an automated testing system. The motor side has a manual knob, allowing manual rotation of the table surface when power is off or during debugging, facilitating coarse adjustment of the optical path.
The application scenarios are wide-ranging: adjusting the angles of mirrors, prisms, and polarizers in the optical system to achieve precise angle alignment; laser scanning and marking systems to control the rotation and indexing of workpieces; semiconductor wafer inspection and micro-nano operations; testing the angular response characteristics of photodetectors; precise part indexing processing; biomedical imaging and automated assembly in scientific and industrial scenarios.
Relying on Sefan Optoelectronics' over 20 years of accumulated precision motion control technology, 7SRA5100B has been rigorously verified in terms of structural rigidity, transmission accuracy, and closed-loop stability. It is a cost-effective choice for high-precision electric rotary tables in China. The closed-loop does not lose steps, the hollow structure does not block light, and heavy loads do not wobble - 7SRA5100B ensures precise and controllable every degree of rotation.
Link Microblog
