The ultra high-performance robot with large workspace

SigmaTau is developed for the most demanding applications of accuracy, rigidity, and dynamic performance

The robot achieves superior rigidity, accuracy and dynamic motion performance due to the lightweight eight-link SigmaTau parallel kinematic concept.

The solution provides a high-level of flexibility and can integrated with other production equipment, be installed on a regular industrial building foundation and can even be reconfigured and moved after initial deployment.

Integrators and machine builders can use the SigmaTau modular system to efficiently design and deploy high performing solutions for advanced manufacturing

We welcome integrators and machine builders as partners to jointly develop solutions based on the SigmaTau robot.

For manufacturing companies dealing with large parts, we can provide assessments, demonstrations, prototype productions. We can also work together with your local integrators or connect you with our current partners to provide process expertise.

Product facts

  • High accuracy and rigidity over large workspaces

  • 5 or 6 axis with high orientational stiffness

  • High-dynamic and heavy-duty configurations

Why Parallel Kinematics?

Robots based on parallel kinematics bridges the gap between CNC machine tools and traditional arm robots. Their parallel load-bearing structure enables them to absorb high process loads and maintain a high rigidity and precision.  Further weight reduction increases their speed and minimizes intrinsic inertia.

SigmaTau top features

Superior rigidity

SigmaTau offers a stiffnes and rigidity that makes it ideal for heavy-duty processes including machining

Hybrid manufacturing

For Hybrid manufacturing setups with need to change tools frequently

Low weight

Lightweight high-dynamic mechanics


High accuracy for tolerances down to 0,05 mm

In-line high speed machining

The SigmaTau robot can be installed around an assembly line to perform precision processes such as machining in-line, along with the production flow.

This gives far higher efficiency than a CNC machine tool which would require its dedicated floor space and often a separate robot for machine tending to perform the same operations at a slower pace. Due to its high installation flexibility, a SigmaTau robot can even be moved and reconfigured for different setups.

The lightweight mechanics allows high dynamic motions with 2g accelerations to minimize cycle times.

Suitable parts include large weldments or castings that require finishing machining (such as milling, drilling, tapping) or high-speed laser processing.

Modular SigmaTau components

The SigmaTau arm system is mounted on three linear motion rails on a customized machine frame. The flexible mechanical structure has minimal requirements on relative alignment, which allows for a quick and easy assembly process followed by a kinematic calibration.

The robot consists of a 5 or 6 axis wrist mechanism, three guiding blocks, and eight links, which are arranged to provide a lightweight but still rigid manipulation.

The workspace can be customized by selecting different link lengths while the guiding blocks remain the same design regardless of workspace size but are available for different loads and rigidity needs. They are designed with Finite Element topology optimization to further reduce weight without compromising rigidity.

Versatile Tool Configuration for Hybrid Manufacturing

SigmaTau is a versatile robot with a broad range of capabilities. Suitable for shops with frequently changing production needs, looking to utilize their equipment to a maximum. Applications include milling, drilling, tapping, welding, additive manufacturing, along other processes.

Configured with a 6th axis addon around the spindle, the robot can be utilized for both 5-axis machining and 6-axis processes, such as welding, with a quick tool attachment without impacting the milling spindle.

The flexibility to change between processes simplifies the planning and maximizes equipment utilization.


Friction Stir Welding
Laser Welding
Additive Manufacturing
Fiber placement

The SigmaTau robot is uniquely designed to fill the gap between CNC machines and traditional robots.

Klas Nilsson, founder of Cognibotics

Take a look at our product news!

Cognibotics signs agreement with Spectrum Technology and ADDICT3D to integrate the innovative Parallel-Kinematics (Sigma Tau) and Hybrid-Kinematics (HKM) robots, and to generally improve Motion Precision in robot automation. LUND, December 07, 2022 – Spectrum Technology and ADDICT3D, both part of Spectrum Group, will …

Combine multiple process tools in the same robot to maximize efficiency and minimize handling time between process steps.

The SigmaTau offers great support for application where stiffness and high precision is key. This makes it ideal for friction stir welding offering several advantages over more traditional welding to preserve material characteristics and increase the strength of the welds.

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