For the 3d printed project, I really wanted to create a piece of jewelry. After talking to Bisesti, we found the Mobius bangle – a really cool design that could be scaled and sized and created in TPU in order to fit into the gum ball capsules. However, after attempting to print two on the TPU-loaded Prusas, I realized that not only were the small details of the design hard to print cleanly in TPU due to the elasticity and stretchiness of the material, but also the supports were really difficult to cut off (as seen on the picture below of the back of the project) but due to the design, they were evidently necessary.

After much deliberation (and a week out of town), I decided to switch the design to a single chain bracelet. With interlocking parts, no matter the size of the bracelet, I assumed it could fit into the gum ball capsule. For this, I decided to try PLA instead, using the Bambu printers for the first time. Here, I ran into a ton of different problems. During the first several attempts (I think 8 if I counted correctly), there were issues of the print popping off the raft and supports during the print, ranging from in the first ten minutes to an hour in. One of them was 80% done and popped off, ruining the entire print.

To combat this, with the help of a lab tech and our TA, Luke, I increased the raft layers to 7, giving the print a more stable and heavy surface to attach to. We also added more supports attaching the print to the raft and the top parts of the chain to a support as they were “floating”, in order to prevent individual pieces of the chain from flying around as the print was being printed. After printing a successful print at 3.5 inch diameter, I realized the size was a bit too large. I experimented with printing at a 2.7 inch diameter, which was still a bit large for my wrist, but the links were at a perfect size to which they didn’t fuse together, which was one of my worries. I also printed one of the bracelets on the PRUSA using PLA.

As seen below, the supports and raft did end up wasting some material and leaving some leftover scars on the actual product, but in the end, it was necessary in order to get a perfect print! The result is a bracelet size chain that can be worn and is fully functional.

After each print, I snapped off the raft and supports, cut off any significant scarring from the supports, and attempted to sand down each edge to ensure a smooth-to-touch finish, however due to the small interlocking links, sanding proved to be pretty difficult.

The last step was to place them within the gum ball capsules with a label of who created the file and the modifications I made. I experimented with spray painting the print metallic silver, but it looked kinda wonky, especially with the leftover scarring of the supports, so I decided to leave the prints white. If I could do this project again, I think I’d like to modify the number of chain links to make the project a bit smaller in terms of length. Currently, it fits on my wrist but is pretty large.

Cost Analysis

Labor: 10 hours x $10/hr = $100

TPU material: $0.38/print (x2) = $0.76

PLA material: ~ $0.48/print (x6 successful, 8 unsuccessful) = $6.72

TOTAL = $107.48