Why large machines need rotary tables
A rotary table acts as an additional controlled machine axis. It changes workpiece orientation without remounting, gives the tool access to different sides and supports operations involving workpiece rotation.
Model 97.055 can be installed with single-column or gantry machines. It supports milling and turning, including vertical turning, and positions tank structures within an FSW system.
The heavier and larger the workpiece, the greater the cost of remounting. A controlled rotary axis reduces setups and helps preserve one coordinate system between successive operations.
Main structural components
The main components of model 97.055 are the base, faceplate, rotary drive, mechanical locking mechanism, absolute position encoder and adjustable supports. T-slots in the faceplate secure fixtures and workpieces.
The base carries workpiece weight and process loads. The encoder reports actual angular position to the controller, while the locking mechanism relieves the drive and holds position during operations requiring greater rigidity.
Adjustable supports simplify alignment during installation, but overall accuracy also depends on foundation quality, concentricity, drive tuning and CNC compensation.
Two servo drives in a master–slave configuration
Model 97.055 rotates using two servo drives in a master–slave configuration. One channel commands motion, while the other synchronises with it to deliver the required torque and control load jointly.
This arrangement distributes force between the drives on a heavy faceplate. Precise tuning is essential: torque or position mismatch can add load to the mechanical transmission.
CNC integration must consider synchronisation parameters, encoder feedback, braking logic and transition between rotation and mechanical locking.
Model 97.055 specifications
An industrial rotary table is defined not only by diameter and load capacity, but also overturning moment, rotational speed, self-weight, drive power and fixture mounting system.
The following specifications apply specifically to model 97.055. For a new project, they illustrate the structure of a technical specification but do not replace calculations for the actual mass, centre of gravity and machining conditions.
| Parameter | Value |
|---|---|
| Faceplate diameter | 5,000 mm |
| Maximum load capacity | 80 t |
| Maximum overturning moment | 300 kN·m |
| Rotational speed | up to 1.5 rpm |
| Lockable indexing increment | 1° |
| Main T-slots | 8 pairs |
| Auxiliary T-slots | 8 pairs |
| Total mass | 40 t |
| Power consumption | 20 kW |
When mechanical locking is needed
A servo drive can hold position, but heavy machining benefits from separating positioning from load-bearing restraint. Mechanical locking carries some torque without continuously loading the drive.
This is particularly useful for indexed machining: the table rotates to a specified angle, locks, and the operation proceeds. For continuous turning or synchronised machining, it instead acts as a controlled rotary axis without locking at each position.
The specification must therefore identify operations requiring continuous rotation and those requiring high static rigidity after positioning.
Rotary tables in an FSW system
FSW machines use rotary tables for cylindrical and tank structures. One system configuration includes two tables with 5 m faceplates.
For circumferential or circular welds, workpiece rotation must be coordinated with welding tool position and process speed. For longitudinal operations, the same tables can locate and hold a large structure.
Integrating the table into the CNC control system creates a unified cycle of locating, edge milling, positioning, welding and subsequent operations without unnecessary workpiece removal.
Selecting a CNC rotary table
Load capacity is only the first parameter. The centres of gravity of the workpiece and fixture, maximum overturning moment, cutting forces, required speed and angular positioning accuracy must be known.
Next define indexed or continuous operation, mechanical locking needs, feedback type, fixture mounting, compatibility with the existing CNC and available working space.
A large table also requires foundation design, installation logistics, service access and safety zones. Together, these requirements determine actual production suitability.
Sources and technical materials
- “Sespel Rotary Table 97.055” presentation — Sespel technical materials
- Product materials in the Sespel website’s Machine Tools section
The applicable regulatory requirements depend on the product’s intended use, industry, jurisdiction and project specification.