## 4 Experiments
### Data Generation and Data Aquisition  
The basis for the data for the classification experiments is formed by printing and scanning the test components. In order to obtain at least 100 unique scans for each class, first the classes must be defined. For each printed component, solid layers and infill structures are generated, which is why these two layers are considered separate classes. However, their classification is not a decisive aspect of the problem under consideration. Nevertheless, they are included in the data collection, as they are suitable for a complete component description in further analyses. Successful material reinforcement with continuous fiber or wire ensures an elevated load-bearing capacity of the component. In the event of faulty reinforcement, the component may fail unexpectedly. It is therefore important to identify poor reinforcement layers. This should be possible without the need for human control during the printing process. Therefore, the classes \"wire good\" and \"wire bad\" are defined as separate classes. This enables printing to be aborted in a production environment if a poor reinforcement layer is printed since the required mechanical properties can no longer be guaranteed. The situation is rather different for solid and infill layers. If an error occurs with solid and infill layers, this can be corrected by overprinting and re-melting during subsequent print layers. Following four classes are therefore distinguished:  
* 'Solid';
* 'Infill';
* 'Wire good';
* 'Wire bad'. As illustrated in Figure 3, the four classes are made up of a total of seven variants. Two different patterns are printed for the reinforcement layers with wire and the infill structure. The test component is a combination of both variants. As is usual in the application, solid layers are printed first. This is followed by infill layers, which can be reinforced with wire. If co-extrusion does not occur as intended, bad layers are created. These are layers in which the wire does not remain in the desired position. There are many causes behind these failures:  
* Insufficient bond between thermoplastic and wire;
* Clogging of the nozzle;
* Lack of wire feed due to a malfunction in the feed unit (e.g., too little friction between wire and feed wheel);
* Wire breakage due to excessively small bending radii;
* High feed speed, causing the wire to detach from the hot thermoplastic. All these factors lead to an unsatisfactory print result. It is possible to correct geometric or design errors. However, process-related errors such as wire breakage can not be completely ruled out. During data generation through printing experiments, attention was to be taken to the repeatability of the experiments. Care was taken in creating the machine code to ensure that no unnecessary systemic influences from the extruder trajectory planning had a negative impact on the quality of the wire reinforcement under investigation. In addition, the experiments were consistently used with consistent materials to ensure maximum repeatability with regard to the materials. This is limited by the influence of the ambient climate, as the experiments were carried out in a laboratory without air conditioning, meaning that room temperature and humidity had at least a minor influence on the processes. Using a dedicated command in G-code, the laser line scanner can be traversed linearly over the component in parallel with the extruder in order to capture the height profile of the printed component. The height profile is saved as a CSV file using a proprietary program. The process for creating the data is divided into three main sub-processes:  
* First, a layer is printed;
* Subsequently, the scanner is traversed over the printed layer;
* Finally the captured data are saved in a CSV file. In this way, a specific CSV file is created for each printed layer. The data can be transferred to other programs for further processing.