Reconstruction of the water pump cylinder head
3D scanning as a base for digital documentation of parts manufactured with traditional methods
3D scanning is becoming more and more frequently used in many different industries, and they have become an inherent element of modern factories, where they are being used in a variety of applications, such as for quality control and reverse engineering. Models created as a result of 3D scanning became valuable digital technical documentation that can be reused for the reproduction and modernization of parts. Such documentation is especially significant when there is no traditional documentation preserved. Over time, frequently used devices deteriorate and if the traditional documentation is not available or damaged, it is not possible to replace the worn part by purchasing a new one.
The Fire Department in the town of Lhotky - Kramolna in the Czech Republic had to face a similar challenge. The fire pump cylinder head, made out of metal alloy craked as a result of the water freezing. Attempts to repair the broken part with brass welding have proved ineffective.
3D scanners as a perfect tool for the precise reproduction of complicated shapes
Due to the lack of documentation, to obtain a mold for casting to produce a replacement for a broken part, a decision was made to 3D scan the worn piece of the water pump. The service was provided by METOS company, which is a certified Scanning Center of SMARTTECH.
To create a detailed, accurate 3D model, a 3D scanner with high precision, dedicated for reverse engineering projects was used - MICRON3D green with a resolution of 5 Mpix. This model, like every SMARTTECH 3D scanner, is certified in accordance with recommendations of German VDI / VDE standards. It allows to acquire information about the shape of an object with a geometrical accuracy of 0.06 mm. 3D scanning with SMARTTECH equipment allows for fast and convenient collecting of information about scanned objects geometry, even highly detailed ones with complex geometry, regardless of their size.
Automatization of 3D scanning for speeding up production
The damaged part of the water pump cylinder head was scanned on the turntable to obtain comprehensive information about its shape. The use of a rotary stage significantly shortened the scanning processand made it much easier. The software dedicated to the MICRON3D green stereo 3D scanner- SMARTTECH3Dmeasure, enables to automatically combine the measuring results collected from different directions The intuitive menu and advanced algorithms of the software allow reducing the human factor, and by that- minimize the possibilities of mistakes appearance. Thanks to this scanning can be properly carried out by a non-technical person.
Precise data about the shape of the cracked pump cylinder head was acquired by displaying green LED light stripes on the element. The information about the curvature of the stripes on the surface was calculated into points with X, Y, Z coordinates. They reflected the object in a form of a point cloud.
The next step of data processing was to create a triangle mesh which is an optimal representation of the real object, based on the cloud of points. That kind of data can be saved in universal formats such as STL or OBJ for further technological modification or can be loaded directly into a 3D printer or CNC machine.
Combining 3D printing with casting technique for precise reproduction
The digital copy of the object created this way was saved as documentation, and its duplicate was modified to fix the damages and used to develop a CAD modelIn the next phase the corrected 3D model became a the base for printing the sand mold. Thanks to the 3D printing technique the process were fastly completed was, The cast from the printed form was scanned as well and compared with the 3D model of the original part.
Comparison of both models results with generating the color map of deviations, which precisely showed the areas of damage on the original element.
The use of modern technologies in the form of 3D scanning not only ensured the perfect fit of the new pump element. It also provided very valuable technical documentation of the historical machine.
3D scanning technology allowed the Fire Department to quickly and easily reproduce the broken element. What is more, the 3D scanning provided the possibility of applying changes to the digital model without the need of creating a physical representation of the pump part, eliminating any waste of material.
With the use of traditional methods based on manual measurements, the process of reverse engineering would be much more time consuming and require multiple adjustments of the handmade CAD model, as well as the physically manufactured part to fit the new element with the existing pump.
Authorized Scanning Center
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