And now I'm going to describe the steps of this process of design and construction, showing the general methodologies, strategies for organizing work, and the tricks to avoid the biggest problems. I will not go into details of the design and development of each individual component because it's too long, but I will give an indication of where to find the information for further study, where possible.
At the very beginning, I chose Pepakura to obtain flat surfaces from the 3D model: because of that I decided to exploit the possibility of using the manual way to unfold, by defining the maximum height of the final model.
In the drawing, that I decided to use, there is a scale reference bar, which indicates the actual size of three meters (I suppose). So I brought in Sketchup the image size so that the bar reference measured three meters also in the drawing. Then I created two copies of the drawing and I placed them squarely.
I chose the scale 1 / 33, so what in the model is 10 cm high, in the drawing (reality) is 330 cm high. That is why in all my drawings there will be a box 330 cm tall as a reference.
Then in Pepakura, to Unfold the model, you have to uncheck the option "Auto" next to the button "Unfold", and in the panel "Parts Layout" and to set to 100 mm the Height in the "assembled size" frame. Obviously in the design we have to put no part of the model higher than 330 cm!