Rotary unit for 3D interior inspection | Phi positioning system for diesel engine inspection


High-precision 360° camera inspection

This high-precision rotary stage was developed especially for 3D camera inspection of the cylinder wall of diesel engines. The positioning system allows measurements in the µm range and is adapted to rough conditions with heavy contamination.

  • High-precision 360° 3D inspection due to an extremely flat rotating unit with a height of just 40 mm
  • Up to ± 0.012° repeatability under extreme measuring conditions such as dirt and hard clogging
  • Low-maintenance operation due to the internal meander structure
Optionally expandable:
  • Adaptation to further loads
  • Integration into the customer-specific application
  • Immediate use with pre-configured controller incl. exemplary software

Maximum stiffness and robustness

A special feature of this rotary unit is that it has been designed for very high moments of inertia. The task was to rotate a centrally positioned arm with a length of up to 1.8 m and two cameras at the ends in a large marine diesel engine in order to be able to take pictures of the cylinder walls. The camera images can be combined into an overall view of the cylinder interior via the position information of the rotary system. For this purpose, the rotary system is inserted through the gas inlet slots of the motor, which limited the height of the rotary unit to 40mm.


The task was solved by designing two clamped thin-section bearings, which provided necessary rigidity through their large diameter even at a low height. A very precisely manufactured crown wheel, which is driven by a motor-gear-encoder combination, is fixed on this turntable that is mounted in this way. The drive can be adjusted backlash-free relative to the crown wheel. The camera data transmission  was realized via a central plug in the turntable, which was connected to an internal slip ring. Furthermore, great attention was paid to the robustness of the system, as rough environments and hard knocks were to be expected. In order to protect the inside of the rotary unit from impurities, the overlapping area of the turntable and base body is designed as a meander structure.

Individual extensions and customizations

Engineering services include the fitting of the systems to your structure and the desired controlls. Furthermore, we develop prototypes and like to adapt the systems to the environmental requirements of your application particle emission, radiation, temperature, precision special parts manufacturing, working height, collision protection, safety concept, compensation factor and filter, sensor mounting, brake, decoupling, special lubrication, special colors, holders, adapters, special motors with pharmaceutical approval, comprehensive documentation, test protocoll, llife cycle tests

Fields of application

Automatic Optical Inspection (AOI), Cylinder Inside Measurement, Diesel Engine Inspection, Surface Inspection, Inspection Systems, Tool Measurement



Lift [mm; deg] n x 360
Positioning speed [mm/s; deg/s] 15
Repeatability unidirectional

[µm; deg]

± 0.012

Repeatability bidirectional

[µm; deg]

± 0.02

Max. Load








Crown Wheel





Specifications are subject to change. Values are for the single axis with our controller. Parameters shown here are typical values for a standard configuration. By customization and given in depth knowledge of your application significantly improved values can be achieved.

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Are you looking for the best technical solution?

Get your first 3D design in just a few days:

Dipl.-Ing. Elger Matthes

Phone: +49 (0) 351 88585-0