For this week’s project, I decided to 3D print trefoil menagerie figures as my “impossible” object, employing two 3D printing processes, FDM and SLA, using the Bambu Lab X-1 Carbon and Formlabs Resin Printer. This blog documents the process (both the good and the bad) of producing five 3D figures and the post-processing required to achieve a clean final look.
To start, I selected an “impossible” design from Thingiverse. I selected a Trefoil Stick by mathgrll. Although there were many choices, I chose this specific geometry because of its challenging yet straightforward design, which can be recreated without a 3D printer, and because I liked the overall design. Then, after selection, I printed it out (with the Bambu Labs printer, FDM) to see how it would turn out with supports and if it held up well with 10% infill, a layer height of 0.15 mm, and a wall thickness of 1mm. And it printed well, resembling the original design. Following this, I decided to scale the object to maximize the available volume in the gumball capsule. The dimensions I implemented in the subsequent iterations were 41.63 mm in the x-direction, 37.35 mm in the y-direction, and 27 mm in the z-direction.
However, when printing the four figures with the correct dimensions and on the same plate, the prints failed and resulted in inconsistent layer height. To remedy this situation, I decided to change the angle of the supports from 45 degrees to 35 degrees, and this proved to fix the issue. When I went to print again, all the figures turned out well. Then all that was left was to trim and remove the support structures, and then sand down any of the remnants of the touching points with the supports.
After successfully printing the four objects using an FDM approach, I then printed the final figure using SLA with a clear resin. Very similar to the process of printing on the Bambu printer, I uploaded my file scaled accordingly, used the auto-oriented and auto-generated supports commands, selected the correct resin, sliced the object, and sent the code to the Formlabs printer, AmicableKitten. I then followed the printing steps and let the object print. Then, I followed up by inserting the print into the washer to wash off the excess resin, patting it dry, and then inserting it into the curing machine for 30 minutes at 60 degrees Celsius. Then I post-process this iteration by sanding and trimming the excess supports.
Overall, this project was inherently complex, but it did provide an opportunity to familiarize myself with the possibilities and purposes of different 3D printing processes.
Cost Analysis
Labor:
Labor: $21.75
3 hours (At Texas minimum wage) = $21.75
Equipment: $1.62
Maker Space (One month membership, includes all the tools and machines used to construct this project) = $50 per month, $1.62 for a day
Materials:
PLA: $3.99 for 200 grams. $19.99 for 1 kilogram
Resin: $3.99 for 50 ml. $79.99 for 1 liter
Picture of cleaned workspaces
Total: $31.35
