28/06/2022 – “Opti Sort” with next generation “SFS” Technology

Sorting and inspecting machines

Gefra GmbH continuously improve their systems for the benefits of their customers, therefore they have advanced their “SFS” System (SFS = shape from shading) and are able to include all necessary components into a smaller camera system including the extensive lighting.


Sorting and inspecting machines „Opti Sort“. © Gefra


Sorting and inspecting machines „Opti Sort“. © Gefra

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The “SFS” technology uses several images with different directions of lighting. These pictures are combined together and calculated by an algorithm to one single image. As a result, an image is produced containing all shape information of the surface. Every small surface defect can be shown and detected very effectively.

The new computer system Gefra has developed allows them to increase the speed with “SFS” from top and bottom up to 700ppm. The smaller ring light allows to change the position between top and bottom that they will have a much better image which gives a very good result.

Furthermore is it possible to develop and upgrade this system in house at Gefra, giving the benefit of a short reaction time and updates to our customers.

Due to the fact, that the correct lighting position of the “SFS” process is mandatory, they use servo motor driven axes to set the position of the flash lighting. With this, Gefra customers gain time and secure inspection quality to set the correct lighting within a few seconds, when changing to the part which will be inspected next. The machine saves all necessary data of the lighting position in the part data list.

Gefra offer two main machine designs, a steel ring type for inspecting screws and long rod-shaped parts, and a glass ring design for inspection of nuts, washers, rivets, and other flat parts.

Their range begins with screws in diameter of 1,4mm and goes up to 18mm. Length of screws can be inspected up to 160mm. Inspecting ratio up to 2,000ppm depending on size and inspection equipment. For flat parts with a surface up to 90mm x 90mm.

Their portfolio begins with inspecting measurements of production parts as for example, shaft diameter, head diameter, thread quality, and so on. Further they can inspect surface defects, scratches, cracks, symmetry, straightness, flatness, ovality, and differences of material quality or hardness. Equipped with a color camera, it is possible to detect deviations of colors on the surface e.g. coating errors. Gefra also offer loading systems and packaging stations which are also controlled by the machine.

Their software system “Gefra Auto Control” is easy to use with a minimum of training and developed to an operator friendly standard. The user does not need any programming skills nor any profound knowledge of computer systems.

It is possible to do trainings for operators at plant or at Gefra site. They have an end inspection of all machines in house at Gefra and technicians who install the machine at customers location on site. Gefra offer online service via LAN connection and team viewer.

Their inspection data can be passed through to customers product data acquisition system, and Gefra “Opti Sort” machines are able to correspond with peripheral machines such as packing stations or loading belts.

Gefra GmbH
Nisterbergerweg 12
57520 Friedewald, Germany
Contact person is Torsten Viebahn
Tel.: +49 2743 930012