by Claudio Cosci IZ1JFK
I would like to share with astronautics enthusiasts the model of the International Space Station, that I made using 3D printing. How was the model born? When the man reached the Moon, I was two years old, I was too young to enjoy that moment but that night, something remained inside me. Growing up, my passion for space missions and the history of astronautics took me, up to the fateful date of April 12, 1981, when the Shuttle era started with the STS-1 mission of Columbia. It was immediately love. Other important moments were: 1992, when Presidents George H.W. Bush and Boris Yeltsin signed the space cooperation agreement between the United States and Russia, giving way to the Shuttle-MIR joint missions; and 1998, when the Zarya module, the first of the long series of modules that are put into orbit, is launched giving birth to the ISS. In the meantime, technology on Earth has grown and another passion that has greatly interested me is 3D printing.
So today the two passions converge and thanks to INTERNET, where there is more or less any information, I have designed, printed and assembled a model of International Space Station in 1: 100 scale.
To create the model, it took 40 hours of CAD drawing.
The program I used is FreeCAD, modular Open Source parametric CAD based on the Open Cascade development platform.
Having my 3D printer a print plate that accepts maximum part dimensions of 180 x 180 x 180 mm, I had to divide the model into thirty eight parts, all exported in the .STL format, Stereo Lithography interface format or acronym for Standard Triangulation Laguage.
An .STL file represents a solid whose surface has been discretized in triangles. More specifically, all inside the .STL file, also readable with a notepad, there are the X Y Z coordinates repeated for each of the three vertices of each triangle and a vector to describe the orientation of the normal to the surface. The .STL file also contains the parameters necessary for setting the printer. I treated thirty-eight STST files with the Ultimaker Cura 4.3 slicing software and the individual parts are printed with PLA extrusion material. PLA or Polylactic Acid, simplifying, is a thermoplastic polymer used on a large scale in rapid prototyping. It derives from the grinding and fermentation of corn and a certain environmental condition is to be considered biodegradable. The extrusion process of the parts required about the mineral with a set layer accuracy of 0.2 mm and an extrusion speed of 60 mm / sec. The different colors of the parts, black, white, orange and gray, are given by the basic coloring of the PLA used. For the final assembly of the model, I used Loctite 401 glue. The model is finished as aa x aa x aa dimensions and a total weight of aa Kg. The dimensional specifications are necessary for the design of the modules, obtained from various PDFs available on the official NASA website.