First, my partner and I selected a 3D model that we both found interesting. When we chose the print, we wanted to create something that would look great on our lab desks, especially since we are both in the bioengineering field and fascinated by cellular processes. For our initial test print, we decided to print Prunella vulgaris (https://3d.nih.gov/entries/21114) , which is a self-healing pollen and has medical uses.
Fig.1 Initial model
Fig 2. FDM print of initial model
After choosing a model, we downloaded the file and loaded it into Bambu Studio Slicer to get prepare for FDM printing. Since we were both new to 3D printing, we quickly decided to keep the default/recommended settings. Once the print job started, we watched the printing of the first layer as instructed. The final product revealed an intricate internal support structure,which later proved to be difficult to remove, due to tightly packed strips.
Unsure of how to resolve these issues, we decided to take a different approach rather than adjusting the settings and reprinting the same model. For our next attempt, we selected the human enzyme pyruvate dehydrogenase (https://3d.nih.gov/entries/3DPX-002368), which is a crucial enzyme in ATP production. This model was easier to print, because its initial structure seemed sturdy and internal supports were not needed. In addition it to this, it was visually more impressive. As before, we monitored the first layer to ensure a smooth start. Once the printing process was complete, we carefully removed the model from the printer and we were thrilled with the final result.
Fig. 3 Pyruvate dehydrogenase 3D print
Exploring a Different Printing Method
For our next (replication) model, we decided to use SLA printing. This time the software we used was PreForm Slicer. A lab technician advised us that removing supports might be a challenge with this material, so we decided to disable them. However, we quickly realized that this software operated quite differently from the previous one. The software was more intuitive and wouldn’t allow us to modify the print setting. No matter how many times we adjusted the parameters, the software insisted on adding supports. We questioned the software, but one of the lab technicians explained that some modifications are not possible, if the software finds them unsuitable. We proceeded to print.
Fig. 4 PreForm Slicer software, picture of the supports
Fig.5 SLA printing
Unlike FDM, SLA printing involves two additional steps: washing (to remove excess resin) and curing (to harden the material), as the material remains sticky after the printing process. A lab technician handled the washing for us and left the print out to dry. The next day we proceeded with the curing process.
Initially, everything seemed fine, until we noticed that an entire section of the print was missing! We consulted with Dr.Wettergreen, who explained that the printer did not register some areas of the structure and encouraged us to reprint it by implementing some modifications to the model. The lab technicians also pointed out that the amount of resin might not be enough. With these answers, we decided to simply reprint the model by slight adjustments in terms of rotations. Thankfully, the second attempt turned out perfectly! Our prints were now fully intact and ready for post-processing and finishing.
Fig 6. Missing part from our first SLA print
Fig 7. Second try! Successful print
Fig. 8 Two models side by side (left-SLA, right-FDM)
Final Touches: Post-Processing and Painting
Cleaning up the SLA prints turned out to be more challenging than expected. Unlike the FDM prints, which snapped apart cleanly, the supports on these prints were more flexible and stubborn. Instead of breaking off easily, they left behind small bumps that needed careful sanding with P120 sandpaper. Once the surface was smooth, we moved on to painting. Our vision was to create a layered effect, starting with a dark purple base, followed by a lighter purple coat and a glossy finish. After applying the lighter shade, the prints ended up looking more worn and faded than expected, which is why we added another layer of dark purple before sealing everything with a protective clear coat.
Fig. 9 First coat of paint
Fig.10 Finished result
Despite the unexpected detour, the final results exceeded our expectations, now we have some awesome new decorations for our lab desks!
The cost analysis reveals that producing an SLA print is significantly more expensive than an FDM print, mainly due to higher material cost.
Table 1: Printing specs
| Technique | Material | Object | Supports | Dimensions | Time | Notes |
| FDM | PLA | Prunella Vulgaris | Internal and external | 2.50 (x) x 2.34 (y) x 1.91 (z) in | 3 hr 4m (30m to design and modify; 2hr 34m to print) | Settings: layer height 0.5mm, outer wall 0.5mm, inner wall 0.5mm; internal supports difficult to remove |
| FDM | PLA | Pyruvate dehydrogenase | External | 2.50 (x) x 2.34 (y) x 1.91 (z) in | 2hr 19m (30m to design and modify; 1hr 49m to print) | Submitted for assignment |
| SLA | Clear V4 resin | Pyruvate dehydrogenase | Internal & external | 2.50 (x) x 2.34 (y) x 1.91 (z) in | 3hr 34m (30m to design and modify; 3hr 4m to print; 10m to wash; 15m to cure) | Piece missing from print |
| SLA | Clear V4 resin | Pyruvate dehydrogenase | Internal & external | 2.50 (x) x 2.34 (y) x 1.91 (z) in | 3hr 59m (30m to design and modify; 3hr 4m to print; 10m to wash; 30m to cure) | Extended cure time since previous print did not cure fully; submitted for assignment |
Table 2 Cost Analysis
Total cost of FDM model: $194-$203
Total cost of SLA model: $733-$1,133
Spray painting is a messy process, which is why we painted our models outside on a cardboard! (Fig.12)
Fig. 12 Station
Fig. 13 Picture of the Protein Engineers
