For this assignment we were assigned to use one of the 3-D printers at OEDK to produce an object that is hard to produce in ways other than 3-D printing. I searched through THINGIVERSE.COM and found this heart gear which was fun to play with:

http://www.thingiverse.com/thing:243278

There are multiple models based on different gear ratios, and I chose the 1:2 model which requires a full turn of the bottom part to turn it back into a heart shape. The parts that made the heart shape could actually be made from casting, but the inner core and the pins are better made with 3-D printer because the structures are complex and hard to make the molds. The parts are printed separately and I think it would be better if I could look for something that could be printed as one part which would be cooler.

I loaded the stl file into the Fortus 250mc printer with the lab tech, Sammy, and did some configurations to the file and it took 14 hours to print. Then the parts were placed into the sodium hydroxide bath to remove the support materials. After another 5 hours there were still some support material inside the core, and I had to use a hook to clear it.

Separate parts:

It took me some time to figure out how to assemble this item. Then I figured out after snapping all pins into the core, I should start from the top and bottom parts because they have distinct shapes, and fit other parts through the gears.

Finished item:

This is a video showing how it works:

IMG_1226