Saarinen's Gateway Arch, lo-poly, 1:1200 scale

prusaprinters

Eero Saarinen's Gateway Arch in St. Louis, MO at 1:1200 scale. Rendered in OpenSCAD according to the official equations as a low poly model with only 134 faces (excluding base). No attempt has been made to render the Gateway Arch National Park ground features around the arch. The photo shows an earlier 1:1600 model printed without support. You probably want to print with support. Print Settings Printer Brand: Prusa Printer: I3 MK3S Rafts: No Supports: Yes Resolution: 0.2 mm Infill: 15% Filament: Capricorn PLA Magical Silky Gold Notes: Print time is about six hours How I Designed This =================== The following paper was an invaluable reference for constructing this model: Osserman, Robert. “How the Gateway Arch got its shape.”Recalling Eero Saarinen 1910–2010. Birkhäuser, Basel, 2010. 167-189. DOI 10.1007/s00004-010-0030-8 While the official equations provide all you need to model the arch, Osserman's paper adds considerable clarity to the process. In summary: the arch is 630′ (192 m) high and equally wide; the cross section of each foot of the arch is an equilateral triangle of side 54′ (16.5 m); the cross section of the top of the arch is an equilateral triangle of side 17′ (5.2 m); the official equations describe the coordinates of the centroid of an equilateral triangle that sweeps out the profile of the arch; the area of this equilateral triangle is in linear proportion to the height of its centroid, ranging from 1262.7⏍ (117.3 m²) at the base to 125.1⏍ (11.6 m²) at the top; the cross-sectional triangle is tangential to the sweep of the arch: it is flat (0°) at the foot and vertical (90°) at the top. The OpenSCAD code is modelled at full scale with a height of 192024 mm. Each half is made up of the union of six hulls defined by thin (1″, or 25.4 mm) extrusions of the cross-sectional triangle. While this results in a few more vertices than strictly necessary, it makes construction simple and manifold. (It isvery helpful that the OpenSCAD idiom circle(…, $fn=3) creates an equilateral triangle centred at the origin, otherwise the code would be much longer.) Half arch construction showing equilateral triangle profiles Category: Buildings & Structures