The ultra high-performance robot with large workspace

SigmaTau is developed for the most demanding applications of accuracy, process load and rigidity.

The robot excels when needs exceed what can be physically achieved with a traditional robot, even together with Cognibotics motion performance solutions. SigmaTau is a parallel kinematic robot bridging a gap between industrial robots and CNC machines.

High accuracy means you will get better part quality and can program the process directly from the 3d models like a CNC machine, without additional sensor systems required on the robot. Our robot has its strongest advantage for larger workspaces, from 2x1x4m and up. It can be configured for multiple processes, and processes requiring force and rigidity. Several robots can independently be integrated in the same setup and combined in highly dynamic processes for a hybrid manufacturing concept.

Whatever your need is we can tailor a SigmaTau robot to fit the job.

Product facts

Accuracy 0,05mm
Forces up to 15kN
Accelerations up to 5G
Scalable work area
Horizontal or vertical mounting
+/- 50 degrees tilting of tool

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

Add, join and remove material with one robot

Low weight

Lightweight high-dynamic mechanics


High accuracy for tolerances down to 0,05 mm

Performance advantages

Parallel Kinematic Robots (PKM) presents several performance advantages over traditional robots. The way loads are shared over multiple links arranged in optimal directions enables a stronger and more rigid tool position. Higher accuracy is also made possible because effects of kinematic variation are averaged out through the structure, rather than being amplified as for a traditional robot. Unlike a GantryCNC machine, the SigmaTau has a well-determined structure which does not create internal stress if there is any misalignment. This allows more flexible mounting of the linear tracks, which in combination with a quick calibration step still provides the same accuracy.

Internal machining

SigmaTau Internal Machining Center Configuration is designed to give maximum flexibility for machining as well as other high accuracy-high rigidity processes on the inside of larger structures. The SigmaTau IMC is built with a lightweight frame mounted on a rotary positioner which can be moved into a large structure. The rotary positioner is used to move the robot to different sectors of the workpiece to achieve a full 360-degree range for the end effector. Suitable industries include aerospace fuselages and large weldments and castings in marine and energy industries.

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Hybrid Manufacturing

SigmaTau hybrid manufacturing for joining, adding and removing material is designed to balance stiffness needed for machining and heavy-duty welding processes (FSW and Induction welding), while still maintaining high dynamic performance through the lightweight structure which is desired for welding and additive manufacturing. The ability to perform both light and heavy processes in one machine eliminates setup and transfer steps between different processes.


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

SigmaTau - Custom Design

Each SigmaTau robot is tailored for the target applications and dimensioned to make most use of the available work area.  We therefor work closely with each of our customers in designing and configuring each robot that we sell. Whether it be the reach of the robot, the size of the work piece, the mounting or desired stiffness.

Contact us to learn more about the flexiblity of the robot and how it can be adapted to fit your specific application.

Curious? Let's book a meeting!