Hollow Rotary Platform vs DD Motor vs Cam Divider: Differences, Advantages and Selection Guide

Comparison of Three Mainstream Rotary Solutions: Hollow Rotary Platform, DD Motor and Cam Divider

DD Motor: Peak Performance with High Cost

The DD motor adopts a direct drive scheme with zero backlash, and its repeat positioning accuracy can reach ±0.5-2 arcseconds, the highest among the three solutions. It features 

compact structure, fast response speed, maintenance-free operation and arbitrary angle positioning.

However, it has an obvious disadvantage of high price — the cost of a DD motor is several times or even dozens of times that of a hollow rotary platform. In addition, DD motors have high requirements for control systems, large heat generation and strict requirements for mounting surface accuracy. For most medium and low load precision positioning scenarios, the performance of DD motors is redundant.

Cam Divider: Low Cost and Durable with Limited Flexibility

Cam dividers are mainstream accessories for multi-station rotation at present, with an accuracy of ±30 arcseconds, and special models can reach within 15 arcseconds. High-quality products can be used for more than 10 years, featuring simple structure, strong bearing capacity and low after-sales maintenance.

Its fatal shortcoming is insufficient flexibility — it can only realize fixed equal division (such as 4-station and 6-station) and cannot position at any angle. With the focus on flexible production and frequent product model replacement in modern manufacturing, the fixed indexing of cam dividers is increasingly unable to meet market demands.

Hollow Rotary Platform: Balanced Choice with Optimal Accuracy and Cost

The hollow rotary platform is clearly positioned between DD motors and cam dividers, achieving a perfect balance in accuracy, cost and flexibility.

• Accuracy: The repeat positioning accuracy is up to ±5 arcseconds, close to DD motors and far better than cam dividers

• Cost: Much lower than DD motors, slightly higher than cam dividers with outstanding cost performance

• Flexibility: Supports arbitrary angle positioning, matched with servo or stepper motors with simple control logic

• Hollow Structure: The maximum aperture reaches 150mm, facilitating the passage of air pipes and wires

Zhuochuang’s ZBTR integrated angle series integrates the advantages of servo motors, cam dividers and DD motors with lower cost than DD motors.

3-Minute Selection Decision: Which One Suits Your Scenario?

In short: Choose DD motors for extreme precision with sufficient budget; choose cam dividers for fixed-station indexing and durability; choose hollow rotary platforms for balanced accuracy and cost and flexible wiring demands.