Casting aluminum in ABS

thingiverse

Aluminum Cast in ABS Mold Link to Earlier Casting Project: http://www.thingiverse.com/thing:286521 Instructions I've been exploring metal casting with ABS molds, recently deciding to try aluminum on a whim. I deleted the mold's STL files, but they're not essential – this is a simple design. A tall core forms the inside of the casting and a 2-sided box shapes the outer diameter, while the sprue feeds from the bottom up through a long square hole. I never intended to use this print as a mold for metal casting, and it's indeed poorly designed for the purpose. But it does feature thick sections, which was what I wanted to investigate. Aluminum, being less fluid than some alloys, won't flow and fill thin areas on its own. However, I suspected that aluminum's thermal properties in thicker parts might be sufficient. The metal alloy was poured at 1250F – hotter than necessary, but I aimed to observe the results. The surface roughness, largely due to high temperatures, might have been minimized if poured cooler. Unfortunately, it may not be possible, given how easily the plastic mold decomposes and produces gases that cause bubbles and surface imperfections. The inner diameter of the mold was 1 inch, but the resulting casting measured 0.99 inches in diameter. The outer diameter mold design was 1.25", while the final result was 1.215". It clearly shrunk significantly for this small cast piece. Despite potential issues, it turned out nicely rounded. There were lots of fumes but no fires; a light grey smoke without soot. If we estimate cigarette consumption, I'd say over 100 might equal this cloud volume. The still-very-hot and incredibly soft mold was then quenched in water – immediately producing steaming, sizzling effects for a minute. This project's main goal was to explore material properties and their limits. Results are inherently unpredictable, making the entire endeavor quite perilous. Be cautious: do not attempt this. Never try metal casting unless properly equipped with full knowledge of safety protocols, lest one risks facing medical response teams, police intervention or firefighters. Note on STL Files This ornament design file utilizes Imperial measurements, which may get misinterpreted by some metric-print software as a minuscule 2 mm diameter. To fix this, scale up by a factor of 25.4, if you prefer a different size, go ahead...