Computed Tomography
Object size
The object size is a decisive influencing factor when performing a CT scan. The object size and the generated resolution of the CT scan are significantly dependent on each other. The smaller the object to be scanned, the closer it can be positioned in front of the radiation source and a larger image can be projected onto the detector. Finally, the scan data is generated from this. The CT scanner we use allows us to scan objects up to a size of approx. 200*200*200 mm.
Material / Substance
Another factor that influences the result or the general feasibility of the CT scan is the material of the object. With increasing material density, the determination of the component surface becomes more difficult. Due to the high material densities of metals, the physical limits of computed tomography are quickly reached.
Wall thickness
For a CT scan, the wall thickness of the object must always be taken into account. The more massive the surface to be scanned, the more the generated CAD data will deviate from the original component. It must always be taken into account that an object is rotated 360° during scanning. For this reason, the component can have a large area to be scanned in the corresponding orientation to the beam source. With large geometries to be scanned through, artefacts are more likely to occur. These artefacts lead to a distorted image of reality being generated during data reconstruction. To illustrate this effect, a nominal-actual comparison of a gyroid made of tool steel was created. A red area can be seen in the middle area of the face. This red area signals that the generated CAD data is larger at this point than that of the original gyroid.
STL data creation
After the CT scan process of the 3D-printed component, the generated information is converted into a surface model (STL). The described factors of object size, material and wall thickness have a direct influence on the quality of the generated STL data.
Target/actual comparison
To create a target/actual comparison, three-dimensional information of your 3D-printed component is first generated. The data obtained (actual) is then superimposed on the CAD data provided by you (target) using a specific alignment logic, the so-called best-fit method. In the next step, existing deviations are displayed using a false colour model. The false colour model visualises in which areas the created CAD data of the 3D-printed component deviates from the provided target data. The green area shows a match between the target and actual data. Areas in which the component is larger than the target data are shown in red and areas in which the component is smaller than the target data are shown in blue. Computed tomography thus enables an analysis that covers the complete geometry of the 3D-printed component.
Reverse Engineering
You have an object that you would like to image in 3D printing, but you do not have a 3D model? We will create the appropriate data for you in the CT scan. Against this background, however, it is important to consider that the object must consist of a homogeneous material. If this condition is not met, no clear differentiation between the different materials can be made during the data evaluation. In this case, the creation of the CAD data is unfortunately not possible.