UnionTech Chicago Tunnel models
The solid infill and hollowed models of the Chicago Hancock Tower pre-assembly.
UnionTech, a Chinese vendor of stereolithography (SL) machines, has highlighted the benefits of open source equipment after its 3D printing equipment was harnessed to produce architectural models.
One of the company’s major distributors, RP America used the UnionTech PILOT 450 platform to print two demonstration models of the Chicago Hancock Tower, which were then displayed at the AMUG Conference and RAPID + TCT trade show earlier this year. The deign files were supplied by Chicago Architecture Foundation and Columbian Model and Exhibit Works.
Such is the PILOT 450’s open source nature, RP America was able to use Materialise’s TetraShell software to aid with the design, and Somos’ WaterClear 10122 material, which would enable inspection of the wall structure once printed.
With the TetraShell software, hollowed wall structures with reinforcement, which can be adjusted by modifying the leg length and thickness, were produced. This allowed drain openings to be incorporated into the design to accommodate drainage of complex shapes. Meanwhile, TetraShell was also used to connect two walls into a single, more stable beam section, to give greater structural integrity.
The two versions of the Hancock Tower differed in that one boasted solid, 4mm-thick walls, and the other was built with hollowed walls reinforced internal lattice structures that measured 1mm thick and registered a 50% weight saving, equating to a saving of more than $60 per kilogram. Thanks to the PILOT 450’s, a fine resolution of 100 microns was achieved with a 0.10mm layer thickness, contributing to smooth sidewalls and fine detail. The printer’s 450mm square build volume meant the models, which were built at a 1:50 scale, needed to be produced in two separate parts which were later assembled together. Each model received a brief UV post-cure, while the hollow model was drained through holes placed on the bottom flange with the aid of a centrifugal device.
The goal of the project, per UnionTech, was to produce robust models, with significant weight-savings and material-savings. But upon reflection, UnionTech has seen it as a fine example of how open source hardware can benefit from the available materials and software platforms on the market which are best-suited to the application.
“Open source strategy allows users to future-proof their investment in the eventuality of third parts development of materials and software that either opens new applications or enhanced cost effectiveness,” a company press release reads. “Open sourcing also avoids investing in costly features whose function is blocking third party products, as well as offering the user a choice of world-class materials and software from established market sources.”