**6.4 Automated machine for rapid 3D physical modeling based on wire bending**

The first question of this experiment was about the credibility of both groups of students about the feasibility of automating the MDSU process. 96% and 97% of the novice and advanced students respectively thought that the MDSU process can be automated. Students that do not believe in the automation of the MDSU process justified their answer by stating that such process is not really necessary. We believe that such answers were because they are young and do not foresee potentialities in automating such methodology. From the question that the MDSU process will need a software, 82% and 97% of the novice and advanced students respectively believe that the MDSU process will need a software. Our interpretation of the difference in results is that advanced students have used more software than novice students and therefore they do not see the MDSU process without software. On the contrary novice students have not used so much software as advanced students.

The next series of questions were about the criteria to be considered in the design of a machine that automate the MDSU process. The list of criteria is: design, functionality, manufacturability, execution times, precision, size, feasibility, sustainability, security, easy machine user interaction. For the novice students, the functionality criteria was the most important among all the criteria, followed by manufacturability, execution time, security, then by the design and machine user interaction. For the advanced students the security criteria was the most important followed by the machine user interaction and then by the functionality criteria. Another series of questions were about the criteria students will consider to select if the machine already existed. Novice students selected the precision as the most important factor followed by material optimization and mesh structure. Advanced students selected the precision as well as the most important factor followed by material optimization and mesh structure. The size of the machine was the less important factor.

Another important question was about the students' opinion if the machine will be dedicated to prototypes or final products. 90% of both types of students believe that the machine will serve for prototypes. The last series of questions we asked to the students were about their appreciation of the MDSU-based machine on: reducing complexity, reducing creativity, reducing manufacturing time, and improves work conditions. 49% and 47% of novice and advanced students respectively believe that the MDSU-based machine reduce the complexity of manufacturing 3D Wireframing objects. 49% and 24% of novice and advanced students respectively believe at 100% that the MDSU-based machine will reduce the creativity. This criteria has a more uniform distribution from the 25% to 100%. 75% and 66% of novice and advanced students respectively believe at 100% that the MDSU-based machine will reduce the manufacturing time. Among the set of criteria evaluated in this last series of questions this is with the more believability. The last criterion in this series is about the improvement of work conditions. 60% and 66% of novice and advanced students respectively believe at 100% that the MDSU-based machine will improve the work conditions.

TRIZ-Based Design of Rapid 3D Modelling Techniques with Formative Manufacturing Processes 187

reader can appreciate that many changes must to be done before our first MDSU-based prototype machine will be achieve. With the design process we propose here and its results we will propose a new machine that meets the MDSU requirements. Due to intellectual

property rights we cannot show more details of our first prototypes.

Fig. 8. Basic geometrical forms manufactured with our first prototype.

In this chapter we have proposed a methodology inspired in TRIZ principles to design mechatronic systems for a new rapid 3D physical modeling technique based on formative manufacturing processes. This chapter has several contributions that will be outlined in the following. First, it presents a match between the most important engineering design frameworks: engineering design process, product lifecycle management and project

Fig. 7. Picture of the first prototype.

**8. Conclusions and future work** 

The last series of analysis executed in this experiment was about the students' proposals. In section 5.3 we have provided some examples of MDSU-based proposals. Students were asked to make their proposals without design restrictions; except that all must met the MDSU methodology. Novice student proposals were more oriented to the mesh sub-process while advanced student proposals met well the MDSU process. A comparison among the proposals was executed taking into account the following sub-processes: meshing, folding, sectioning, cut, union, wire size, machine size, continuous feeding, straighten system, diversity of forms capability, folding ranges. It was noticed that cut and wire size was met by all the proposals in both types of students. 92% and 100% of novice and advanced student proposals respectively are machines of considerable size. 83% and 93% of novice and advanced student proposals respectively consider continuous wire feeding. 58% and 53% of novice and advanced student proposals respectively met with the meshing requirement. 67% and 87% of novice and advanced student proposals respectively me the folding requirement. 50% and 73% of novice and advanced student proposals respectively met the sectioning requirement. In general advanced student proposals met the MDSU requirements better than the novice student proposals; except the meshing requirement but not for more than 5% of difference.

### **7. A first prototype**

The current prototype was conceived in a multidisciplinary way almost following the concurrent engineering approach. Three different specialties were participating: industrial design, mechanical engineering and electronic engineering. A professor from each specialty and a Master of Science student from each discipline participated. We had meetings every three weeks. During the meetings the final mechanical design was decided. Once the mechanical design was decided, the electronic design starts to automate the machine. Our first prototype was developed during these meetings. Figure 6a shows the first prototype we developed. There were no design process followed for the first prototype. After the first proposal we carried out some simulations in RhinoTM to detect possible problems. We found some problems that were corrected in the second prototype shown in Figure 6b. The prototype shown in Figure 6a can only make wire bends from ±90°. Figure 7 shows a picture of the real prototype as shown in Figure 6b. Some first tests were executed with basic 2D figures. Figure 8 shows some basic geometrical forms done with our first prototype. The

Fig. 6. First prototypes.

reader can appreciate that many changes must to be done before our first MDSU-based prototype machine will be achieve. With the design process we propose here and its results we will propose a new machine that meets the MDSU requirements. Due to intellectual property rights we cannot show more details of our first prototypes.

Fig. 7. Picture of the first prototype.

186 Industrial Design – New Frontiers

The last series of analysis executed in this experiment was about the students' proposals. In section 5.3 we have provided some examples of MDSU-based proposals. Students were asked to make their proposals without design restrictions; except that all must met the MDSU methodology. Novice student proposals were more oriented to the mesh sub-process while advanced student proposals met well the MDSU process. A comparison among the proposals was executed taking into account the following sub-processes: meshing, folding, sectioning, cut, union, wire size, machine size, continuous feeding, straighten system, diversity of forms capability, folding ranges. It was noticed that cut and wire size was met by all the proposals in both types of students. 92% and 100% of novice and advanced student proposals respectively are machines of considerable size. 83% and 93% of novice and advanced student proposals respectively consider continuous wire feeding. 58% and 53% of novice and advanced student proposals respectively met with the meshing requirement. 67% and 87% of novice and advanced student proposals respectively me the folding requirement. 50% and 73% of novice and advanced student proposals respectively met the sectioning requirement. In general advanced student proposals met the MDSU requirements better than the novice student proposals; except the meshing requirement but

The current prototype was conceived in a multidisciplinary way almost following the concurrent engineering approach. Three different specialties were participating: industrial design, mechanical engineering and electronic engineering. A professor from each specialty and a Master of Science student from each discipline participated. We had meetings every three weeks. During the meetings the final mechanical design was decided. Once the mechanical design was decided, the electronic design starts to automate the machine. Our first prototype was developed during these meetings. Figure 6a shows the first prototype we developed. There were no design process followed for the first prototype. After the first proposal we carried out some simulations in RhinoTM to detect possible problems. We found some problems that were corrected in the second prototype shown in Figure 6b. The prototype shown in Figure 6a can only make wire bends from ±90°. Figure 7 shows a picture of the real prototype as shown in Figure 6b. Some first tests were executed with basic 2D figures. Figure 8 shows some basic geometrical forms done with our first prototype. The

(a) (b)

not for more than 5% of difference.

**7. A first prototype** 

Fig. 6. First prototypes.

Fig. 8. Basic geometrical forms manufactured with our first prototype.
