Products - PI (Physik Instrumente) L.P.
H-855 High-Load Hexapod Family for Precision 6-Axis Positioning of Loads to 500kg
PI introduces the H-855 high-load hexapod family, a modular 6-DOF positioning platform engineered for precision positioning and alignment of payloads weighing up to 500 kg (1100 lbs).
Designed for demanding industrial automation, optics, semiconductor, aerospace, and simulation applications, the H-855 combines high load capacity and six-axis motion in a parallel-kinematic design. Four configurations allow engineers to select a system based on the requirements that matter most for their application: precision and load capacity, speed, installation space, or travel range.
H-855 High-Load Hexapod Family at a Glance
- Payload: Up to 500 kg (1100 lbs)
- Degrees of freedom: X, Y, Z, θX, θY, θZ
- X/Y travel: Up to 320 mm
- Z travel: Up to 150 mm
- θZ rotation: Up to 120°
- Maximum velocity: Up to 10 mm/s
- Minimum incremental motion: Down to 0.15 µm
- Absolute rotary encoders
- Brushless DC gear motors
- Holding brake available
- Modular mechanical architecture
- Application-specific configurations available
- Operation with PI hexapod motion controllers
Four Configurations for Different Motion Requirements
Instead of using a single mechanical configuration for every application, the H-855 family uses a modular architecture that adapts the mechanics to different performance requirements.
The general-purpose model, H-855.H2A, is designed for precision positioning of heavy components and supports payloads up to 500 kg with the base plate mounted horizontally. Typical minimum incremental motion is 0.3 µm in X and Y and 0.15 µm in Z. Typical unidirectional repeatability is 0.4 µm in X and Y and 0.15 µm in Z.
The overview below shows load capacity, velocity, and travel ranges for the other 3 models in comparison with the H-855.H2A.
Model | Payload | Maximum velocity | X/Y travel | Z travel | θZ rotation |
H-855.H2A | 500 kg | 0.5 mm/s | 200 mm | 100 mm | 80° |
H-855.H2AC | 400 kg | 1 mm/s | 100 mm | 50 mm | 50° |
H-855.H2AL | 300 kg | 2.5 mm/s | 320 mm | 150 mm | 120° |
H-855.G2A0B | 260 kg | 10 mm/s | 200 mm | 100 mm | 70° |
Parallel Kinematics for Positioning Heavy Loads
A hexapod differs fundamentally from a conventional stack of linear and rotary stages. Six actuators operate between a common base and moving platform, providing motion in X, Y, Z, θX, θY, and θZ.
This parallel-kinematic structure distributes the load across the mechanism rather than carrying it through a stack of individual positioning axes. The result is a compact approach to positioning heavy components in all six degrees of freedom.
The H-855 uses brushless DC gear motors and absolute rotary encoders. Absolute position information is available after power-up, eliminating the referencing move normally required by incremental positioning systems. For automated equipment, this can be particularly useful when the payload or surrounding machine structure makes a conventional homing move undesirable, and it is a great advantage in a power outage situation.
Adapt the Hexapod to the Application
The modular H-855 architecture allows PI design engineers to play with actuator configurations, gear ratios, travel ranges, and mechanical geometries to meet a variety of requirements, prioritizing parameters such as:
- Payload and holding force
- Positioning performance
- Velocity
- Travel range
- Installation envelope
- Mechanical configuration
Application-specific H-855 variants can also be developed where a standard configuration does not meet the mechanical or motion needs.
Cartesian Control with PI Hexapod Controllers
The H-855 family is operated with PI's C-887 series hexapod motion controllers. Rather than requiring the user to calculate the movement of each actuator, the controller handles the coordinate transformation and accepts positioning commands in Cartesian coordinates.
Work and tool coordinate systems can be changed to simplify integration, and the virtual pivot point or center of rotation can be defined in space. PI hexapod controllers provide TCP/IP and RS-232 interfaces, with optional analog and EtherCat fieldbus connectivity, depending on the controller version.
The H-855 extends PI's hexapod technology to precision motion applications involving substantially heavier payloads. Rather than forcing load capacity, speed, travel, and installation size into one mechanical design, the family gives engineers several configurations for matching the hexapod to the application.
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