Truth be told, it’s more a dolphin than a whale. But the pun was too good to skip out on.
In this week’s 3D printing assignment, I found an “impossible object” to print from www.thingiverse.com. After looking at some example prints around the OEDK, I really wanted to experiment with interlinking parts. Some of my favorite articulated parts were the pangolin and the butterfly. After some searching, I chose an articulated key chain dolphin, shown below. The key chain feature is an added appeal to the design. 
One of the 3D prints was done on the Objet inside the wet lab, shown below. A lab assistant helped me out with setup on the Objet, which was not too involved. Amid some of the printing options, I chose the rigid white material instead of the flexible black material. Upon a recommendation, a decided to opt for a matte finish since the bottom of the print would still be a matte finish even with a glossy setting. After the Objet print finished, the final product had to be cleaned out of the support using the water jet machine inside the wet lab. In my experience, it’s hard to completely clean out an Objet piece using the water jet. I ended up cleaning out the final piece manually after using the water jet.
The other 3D print was conducted on the MakeGear M2, models of which are available for easy access in the Maker Bar. The image below shows the articulated dolphin mid-print. This 3D printer is cool in that the bed is open to the environment. For the purposes of this print, I maintained a layer height of 0.2mm, and set the number of top, bottom, and side layers to 3. Most of the other settings were pretty general, a skirt but no raft, support generation was activated but was not necessary for this print. After the print was completed and the printer had cooled, the print bed was removed (it has a magnetic attachment) and the print was removed. While the print can be removed usually directly from the test bed, I made sure to take the test bed off because I broke my first print in an attempt at taking it off directly. Very little post-processing was necessary.
Both the final prints are shown below. The pink part was printed on the MakerGear and the white part was printed on the Objet. The MakerGear print appears to be slightly more brittle, while the Objet print does seem to be stronger (having survived the water jet machine). The back side for both prints are smoother, but also offered a somewhat unique finish as compared to the parts of the print that were not attached to the print bed.
The final prints turned out really well. To my surprise, both dolphin prints fold over themselves more than I expected. Thus, they are easily tucked into a gumball capsule as shown.
Cost Analysis
The main resources that this assignment relies on are the 3D printers. The filament costs are assumed to be negligible. The cost analysis assumes that we must buy the 3D printers to use them.
- MakerGear M2: $1825
- https://www.makergear.com/products/m2
- Objet 260: $9950
- http://www.stratasys.com/3d-printers/objet260-connex3
- https://www.ebay.com/i/202243289109?chn=ps
- Labor Hours: $30 at $10/hour
