For this assignment, I chose to print out this object: https://www.thingiverse.com/thing:2922835 . It was uploaded by user putridp. It felt impossible to me as the “hoops” that make up each ring are locked together, and aside from forming a material into the proper shape/cutting it and then combining it together again, it seemed like 3D printing was the best option to create the part.
I first attempted the part on the PRUSA Mini. It went well, printing without a hitch.
I was surprised by how well the rings rotated without “popping out,” thanks to the rigidity of PLA. As I printed more, I was disappointed by the quality of the Prusa I3 MK3 full size printer compared to the mini. It was probably my fault for how the printer was set up, but the layers looked messier and I did not get the same fluidity.
The Mini prints are the orange, while the full size printer is the blue. I was also surprised by how much faster the mini printed.
As I ventured into the realm of non-FFF printers, I experienced a good bit of difficulty achieving the desired product with the SLA Printer. I attempted to use the Form 2 printer.
The part appeared fine on completion, but it was unable to rotate between the rings. I suspect that the resin hardened between the layers as the product was printing.
The print time with the SLA was 4 hours, so that was ample time for the resin to potentially harden. Another possibility is that the tolerance wasn’t high enough on this printer. Had I more time, I would attempt to modify the file to greatly increase the tolerance between rings. I was not expecting this issue because the parts printed using FFF had a great deal of tolerance, and some prints had too much and could pop apart. After multiple failed prints and not much time left, I decided to move on.
The curing process was interesting. I was hopeful that the isopropyl alcohol bath would potentially “loosen” the part, but it was to no avail. The time requried to wash and cure the part will be on my mind for future prints.
The different amounts of time and cost are detailed in the table below. The time for the resin was a combination of the printing, washing and cleaning times. The cost was an estimate for the material based on it being $50 per liter (which I found on the internet). I estimated the amount of resin needed as around 25 mL (based on geometry and converting size to volume).
As shown, the MINI was the fastest, cheapest, and I thought it provided the best job for the task. The SLA printing method has a lot of strengths for particular builds, especially using different materials, but for my purposes the PLA FFF worked the best.
I was very happy with how the parts printed in PLA turned out. The desired product was printed, and it printed very well. I also learned a bit about how 3D printing works and about different materials and printing methods.
