For this project, I chose to do the intermediate level so that I could practice modifying premade shapefiles. After exploring Thingiverse, I decided to print a flexi rex with interlocking links that allows its body and tail to move.

Before I began to modify the t-rex file, I used calipers to measure the dimensions of the gumball capsule. These dimensions were a diameter of approximately 1.85 in and a height of 2 in, which are 46.99mm and 50.8mm respectively.

The first 3D printing method that I used was FDM printing. To do this, I imported my t-rex file from Thingiverse into Bambu Studio slicer on the OEDK Maker Bar computer. Using the scale tool, I initially adjusted the size of my t-rex to be 50mm across its longest length. I then set the layer height to 0.15mm and the infill density to 15%. Though I did not notice this when I chose the print, my t-rex did not need supports, so I deselected the supports tab.

After making all of the adjustments, I sliced the piece. I was surprised to see that the print would only take about 30 minutes and cost $0.11. I then selected print plate, chose white PLA as my filament, and sent my print to the printer.

My first print came out great, but was a little small compared to the gumball container. I decided to scale it up to 60mm for its longest length, this time knowing that the links would allow it to bend and still fit in the gumball. I kept all other settings the same. This new size just barely fit into the gumball container. I printed two more of the same size also using white PLA.

To familiarize myself with different filaments, I then decided to make a 4th FDM print using a different type of filament. My first try with the ABS filament was unsuccessful, with strings of filament in a tangled mess. After making sure to clean all the filament off of the plate. I tried the print a second time. This print was much more successful.

The second 3D printing method that I used was SLA printing with resin. To do this, I imported my t-rex file into PreForm slicer on the OEDK computer. I heard from classmates that it was difficult to make pieces that can bend or move using SLA, as joints and link often fuse together. To ensure that my t-rex would still fit into the gum ball capsule with little to no bending, I decided to scale down this print to 40mm. I also decided to make two prints in case I messed up the post processing for one of them. Although I didn’t need supports for FDM printing, I added supports to the SLA print using auto generate. I chose to use Tough 1500 resin and, after checking the resin tank, I sent my print to the correct printer.

After the print finished, I removed the plate from the printer and removed the parts. Then I washed the resin for the recommended time of 20 minutes. Once the washed pieces were dry, I cured it at 70 degrees for 60 minutes. After removing the supports, I had two successful SLA prints. As anticipated, however, these pieces could not bend, but the smaller size still allowed them to fit in the capsules. Since these prints were smaller, I decided to place both into a single gumball.

After putting all of my prints into gumballs and writing the thingiverse user info on slips of paper, I cleaned up my workspace.

Overall, this was a relatively easy and short assignment. This was my first time 3D printing and I am so excited to have finally learned how to use the printers. I look forward to 3d printing many more things in the future.

Cost Analysis:

• FDM 3d printing costs: 0.11(small) + 4*0.17(big) = $0.79
• About 9mL of tough 1500 resin, costing $199/L = $1.80
• Free 3D printer use at Harris County Public Library
• 3 hours of labor, costing $20/hr = $60

Total Cost: $62.59