AsianScientist (Dec. 30, 2016) – In this column, I normally ramble on about current events going on in the space industry in various Asian countries. This month I’ll take a break from that and show you all about a project that I have been working on as part of my PhD at the Singapore Centre for 3D Printing, Nanyang Technological University. It’s kinda space related, as it uses space-certified thermoplastics, so it’s not totally irrelevant for the column.
Over the past year or so, I have been working with 3D printing giant Stratasys to design a 3D printed drone using the wondrous ULTEM 9085 thermoplastic. This plastic in question has been briefly referred to in a previous column covering the Google Lunar X-Prize. Remember the Japanese robot, Hakuto? Those tan-colored wheels are printed in ULTEM 9085.
3D printed drones are nothing new. But what makes this drone unique is that it was printed with its electronics embedded in the structure using ULTEM 9085 plastic, which requires high printing temperatures. Consumer grade 3D printers tend to use ABS or PLA plastics which don’t require a heated chamber.
The problem with ULTEM 9085 is that it undergoes significant warpage due to differential cooling after it has been printed. That is to say, if one section is cooler than another, it will contract at a different rate and cause internal stresses, resulting in warping. For that reason, it is important to maintain a constant temperature across the entire print bed as well as within the print chamber. That temperature is in the region of 160-180 degrees Celsius, far in excess of the operating temperature of off-the-shelf drone components.
The resulting drone is tough, flame retardant, and more importantly, it demonstrates a combined print and assembly process in one step…in principle.
