For this assignment, I started out wanting to print an impossible object that was able to articulate. I downloaded a couple of different fidget toys off of various CAD libraries, such as Thingiverse, GrabCAD, and the Prusa library. Most of my fidget toys printed well on the Prusa PLA printers (although some of them required some force initially to get the parts to articulate), but they were unable to articulate when printed on the Form SLA printers. The takeaway from this is that certain types of printers work best for printing certain types of parts. I think the issue I was having with the SLA printers was that the resin was remaining in the joints and then curing, rendering my pieces static. Another challenge associated with printing an articulating object was the scale we were required to print at. Without the constraint of having to fit inside a gumball container, I would have printed some of my objects at a larger scale, and then they might have been able to articulate when printed on the SLA printers.

I decided to pivot to an impossible knot, choosing the CAD file below to print. This was able to be printed with high quality on both types of printers. I initially printed three different impossible knots before choosing one to proceed forward with to complete the assignment.

Personally, I like the appearance of the PLA knot best. The SLA knots have dimples from where the supports were removed and the dull finish of the SLA is not as aesthetically pleasing as the shiny PLA.

Overall, I enjoyed experimenting with different parts and seeing how things would turn out on the different printers!

Cost Analysis*:

Labor: 2 hrs x $20/hr = $40

PLA: $0.14 x 4 = $0.56

SLA: 16.18 ml x $149/(1000ml) = $2.41

Total: $42.97

*Material Costs Reflective of Final 5 pieces, labor costs reflective of entire time spent