Aluminum heat sink cast in ABS mold

thingiverse

Another cast aluminum part made with an ABS mold. Other metal casting projects: Aluminumhttp://www.thingiverse.com/thing:733205 Pewter, zinc, leadhttp://www.thingiverse.com/thing:286521 Pewterhttp://www.thingiverse.com/thing:288472 Instructions I see a real-world application for direct aluminum casting in an ABS mold here. A heat sink with thin blades is challenging and time-consuming to DIY using other methods. Given what I know about heat sinks, those with thin, long fins have the best "aspect ratio" and can get rid of heat most efficiently. So, I designed a basic heat-sink model that could serve as a useful test case. The fins are 0.04 inch thick by design, and the cast fins come out around 0.039 inches wide. The spaces between fins were designed to be 0.1 inch wide. The base is a 1.5-inch square shape, but I have yet to cut off the bulbous sprue or the rectangular vent. I performed this casting using an in-progress prototype of my broken-arm centrifugal casting machine, which is used by artists, jewelers and dental labs. Centrifugal force pushes the metal into the mold during the casting process. This ABS mold had some issues with its print but was salvaged and put to good use. However, I made a brain-fart design error resulting in nearly 3 hours of failed print attempts, which is why there's flashing across the middle fins. Upon inspection, other defects show up, but they are likely to be corrected by using better mold designs in future prints. For now, let's ignore that ABS residue on some areas of the casting – that will be gone once soaked in acetone. The most interesting result so far remains my satisfaction level upon breaking this out from its mold - you know, unwrapping a gift like any other project... And here comes a little anxiety! Was all that work really worth it? Despite doubts I'm feeling relieved and surprised that it worked. Completely amazed doesn't come close to describing what's inside of me at the moment. Now let’s illustrate with these mold building files for my cast heat sink example - which has room to improve yet: Here is an idea, for now - if interested: try to use your photos "broken arm centrifugal casting" so that this process might make some more sense.