**6. Analysis**

#### **6.1 Freeform construction of 3D objects by means of wire bending**

The first question was about the thinking process followed by students to manufacture the cup by wire bending. The answer options were: top-base-walls, base-top-walls, base-walltop, meshed walls-top-base, meshed walls-base-top, 2D meshed, cut sections and union and other. 33% and 30% of the novice and advanced students respectively chosen the top-basewalls thinking process. 28% and 35% of the novice and advanced students respectively chosen the base-x-y thinking process, where "x" and "y" are base or walls. 30% and 26% of novice and advanced students respectively chosen the meshed walls-w-z thinking process, where "w" and "z" are base or top. In general, the common way to think about manufacturing a cup with wire is to build in the following sequence top-base-walls. There are no significant difference between novice and advanced students. If we analyze the statistics deeper, advanced students start with the base more than with the top (35% versus 33%) but the difference is not significant. In general terms three thinking approaches are found with similar statistics: top, base and meshed walls. Something interesting is that 2D mesh and union as well as sections cut and unions were the less considered thinking approaches. This is interested to us because the MDSU approach is more based on mesh and unions. By investigating deeper, this was the result of the instruction that students must build the cup in a continuous way without any cut. But according to our observations a little quantity of students did the job without any cuts.

To the question about the most used basic figure. 36% of the novice students have chosen the circle while 26% of the advanced students have chosen the triangle. Our interpretation is that novice students were inspired by the form of the cup while advanced students were influenced by the knowledge provided in the finite element course they are taking. Another important percentage was assigned to the mix use of basic forms.

Questions related to the criteria that students have used to chose the proposal to be build by hand were applied (divergent phase). The criteria were: design, structural strength, easy to build and material optimization. 30% and 23% of novice and advanced students respectively considered in 100% the design criteria to select their proposals. With respect to the structural support criteria, 36% and 28% of novice and advanced students respectively took into account in 100% this to select their proposals. 17% and 23% of novice and advanced students respectively considered in 100% the easy to build criteria to select their proposals. Finally, 16% and 21% of novice and advanced students consider in 100% the material optimization criteria to select their proposals. From these results, we conclude that structural support was the most important criteria to select their proposals and therefore the most important design requirement for both groups. The novice students considered this criteria more important that advanced students.

To the question about the time spent to manufacture the proposal, novice students spent between 30 to 75 minutes to manufacture their proposal while advanced students spent between 15 to 45 minutes. The results are as expected, advanced students have more manual skills than novice students. It was observed that some students developed a support to manufacture their proposals. Because of that we asked the students if they consider that is

manufacturing process for the new rapid three-dimensional physical modelling technique), finally the designer is able to propose a machine (design requirements) for new rapid 3D

The first question was about the thinking process followed by students to manufacture the cup by wire bending. The answer options were: top-base-walls, base-top-walls, base-walltop, meshed walls-top-base, meshed walls-base-top, 2D meshed, cut sections and union and other. 33% and 30% of the novice and advanced students respectively chosen the top-basewalls thinking process. 28% and 35% of the novice and advanced students respectively chosen the base-x-y thinking process, where "x" and "y" are base or walls. 30% and 26% of novice and advanced students respectively chosen the meshed walls-w-z thinking process, where "w" and "z" are base or top. In general, the common way to think about manufacturing a cup with wire is to build in the following sequence top-base-walls. There are no significant difference between novice and advanced students. If we analyze the statistics deeper, advanced students start with the base more than with the top (35% versus 33%) but the difference is not significant. In general terms three thinking approaches are found with similar statistics: top, base and meshed walls. Something interesting is that 2D mesh and union as well as sections cut and unions were the less considered thinking approaches. This is interested to us because the MDSU approach is more based on mesh and unions. By investigating deeper, this was the result of the instruction that students must build the cup in a continuous way without any cut. But according to our observations a little

To the question about the most used basic figure. 36% of the novice students have chosen the circle while 26% of the advanced students have chosen the triangle. Our interpretation is that novice students were inspired by the form of the cup while advanced students were influenced by the knowledge provided in the finite element course they are taking. Another

Questions related to the criteria that students have used to chose the proposal to be build by hand were applied (divergent phase). The criteria were: design, structural strength, easy to build and material optimization. 30% and 23% of novice and advanced students respectively considered in 100% the design criteria to select their proposals. With respect to the structural support criteria, 36% and 28% of novice and advanced students respectively took into account in 100% this to select their proposals. 17% and 23% of novice and advanced students respectively considered in 100% the easy to build criteria to select their proposals. Finally, 16% and 21% of novice and advanced students consider in 100% the material optimization criteria to select their proposals. From these results, we conclude that structural support was the most important criteria to select their proposals and therefore the most important design requirement for both groups. The novice students considered this criteria more important

To the question about the time spent to manufacture the proposal, novice students spent between 30 to 75 minutes to manufacture their proposal while advanced students spent between 15 to 45 minutes. The results are as expected, advanced students have more manual skills than novice students. It was observed that some students developed a support to manufacture their proposals. Because of that we asked the students if they consider that is

**6.1 Freeform construction of 3D objects by means of wire bending** 

quantity of students did the job without any cuts.

that advanced students.

important percentage was assigned to the mix use of basic forms.

wireframing techniques.

**6. Analysis** 

necessary some kind of support to manufacture their proposals. 86% and 70% of novice and advanced students respectively think they do not need a kind of support to manufacture their proposals. Our interpretation is that advanced students have more skills and know more tools to develop their proposal and therefore they think in less percentage that they do not need a support.

Because in the first experiment the students manufacture their proposals by hand, a question related to the use of special tools was applied. The results shown that 11% of the novice students and 100% of the advanced students think they need a tool to manufacture their proposals. Furthermore, students were asked about the type of manual tool they need. The results shown that 91% and 94% of the novice and advanced students consider they need tweezers. Other manual tools selected by the students where molds, folding machine, scissors, imagination and none.

An important question about cognition was applied to the students. The question was about generation of ideas about how to improve the formative manufacturing process. 40% and 35% of novice and advanced students respectively feel at 100% that they generate ideas during the experiment. These results show to us that hand manufacturing help to generate ideas (increase creativity).

Recognizing that the final model the students made was a wire-frame model of a 3D object. Students were asked about post-processes needed to finish a 3D object (mock-up). Among the post-processes students proposed are: finishing, structural support, covers, soldering unions, painting, etc. Of the most important for both students were finishing, fixing the support and covering the walls.

One final question about the complexity of the experiment was applied to the students. 8% and 9% of the novice and advanced students considered at 100% the experiment complex. Almost 80% of their appreciation falls between 50% and 75% of level of complexity with a more percentage in the 75%. We conclude that in general students of both levels considered the experiment with some complexity.
