As a rule, rotary indexing tables are used for assembly tasks, such as the production of small electronic components. They pass the components for processing from one station to the next quickly and by the shortest route. However, as the number of workstations increases, the rotary indexing table becomes larger and more confusing. This is where Afag's new LTM horizontal comes in - the space-saving alternative to the classic rotary indexing table. Built from standard components, it can be configured to suit any task. In combination with feeding and handling technology from Afag, design engineers receive an efficient solution for compact assembly systems from a single source.

Standardized solution with a good price-performance ratio
The LTM-Horizontal enables high cycle times and an excellent parts flow. Depending on the feed length, load of the workpiece carriers and position of the center of mass, workpiece carrier changeover times of 0.3 seconds are possible with the new linear module. This leaves more time for assembly at the individual stations. This enables a higher parts output. The repeat accuracy in the running direction always remains constant at less than ± 0.1 millimeters.

Thanks to its relatively small footprint, the use of the Linear Transport Module Horizontal results in a comparatively higher process density than rotary table solutions. It is only 218 millimetres wide without workpiece carriers on the customer side and is available in six different working lengths between 720 and 3,720 millimetres, depending on requirements.

The LTM is easily accessible from all sides. This means that the parts at the individual stations can be processed not only from above, but also from below and from the side. © Afag

Parts processing from above, below and to the side
Between six and 31 workpiece carriers can be processed by workstations on both sides of the module. Work surfaces measuring 118 × 116 millimetres are available for this purpose. The aluminum workpiece carriers are firmly connected to a high-precision and maintenance-free toothed belt that does not need to be re-tensioned. This eliminates the need for readjustments to the system and therefore long downtimes. Payloads of up to one kilogram are possible with the interchangeable carriers.

The LTM is easily accessible from all sides. This means that the parts can be processed at the individual stations not only from above, but also from below and from the side. It is also possible to transport and process protruding parts. "Overall, the LTM-H can handle more complex applications and generally lighter product groups compared to the LTM-V," explains project manager Josef Häfliger. "If the general conditions are right, it is also possible to place additional stations on the LTM to save even more space."

Endless configuration options
The LTM-Horizontal is not only modular and flexible in its design, but also in its drive type. The optional open motor interface allows customer-specific gearboxes, controls and motors to be fitted. These can be relatively small, as only a small mass needs to be moved - this reduces energy costs. Both the motor and gearbox can be attached to the bottom or top of the transport module - straight or at an angle. "With this new development, we have responded to increased customer feedback following the market launch of the LTM-V," says Christoph Böhm, Head of Development Handling Technology at Afag. "With the still efficient concept of the LTM-H, we are now also making the return path of the workpiece carriers usable due to the lateral accessibility. This allows customers to realize more stations in a smaller installation space than before. Another positive feature is that they can place stations directly on the LTM themselves. This allows users to configure their LTM exactly according to their needs, making them more flexible and saving space.

Concrete plans for further improvements
The market is always on the move and constantly demands new solutions and improvements in service and operability. This is why the handling technology development department is constantly working on the LTM Horizontal and the entire LTM series. The systems are constantly being optimized, as project manager Häfliger explains: "Our aim is to further develop the series through successive measures due to the constantly increasing market requirements. There are several concrete plans to further increase accuracy and improve serviceability, which we will gradually implement".