For this impossible 3D printing assignment, I chose to print a puzzle ring. Puzzle rings typically are made out of metal and assembled by breaking each loop and rejoining them so they intersect. When printing this object, there is no separation and reunion required as 3D printing allows the loops to be created already intertwined. In class, I found a deign on Thingiverse by user nivs1978 and immediately started the iterative process of printing.
To start, I wanted to print the original object at scale.
Iteration 1: I oriented the file so the circle of the band was horizontal with the print bed, sliced it, and sent it to the printer. What I shortly learned was that I had sliced the original SLT for use with the Ultimaker which did not have any printing filament loaded. The reason being that students have historically had more issues with the Ultimakers than the Prusas and thus avoid them which leads to the filament drying out so they are only loaded upon request. After watching the nozzle head move around as I realized my mistake, I quickly aborted the air only print.
Iteration 2: Using the same orientation and original scaling, I sliced the file for the Prusa and attempted a second print. Things immediately went pear shaped when the raft stuck but the layers for the actual ring didn’t stick to the platform at all. That didn’t stop me from trying the same thing a second time to see if it was a temperature issue.
Iteration 3: Same orientation and slicing but this time with supports to try to provide more surface area for adhesion. I ended up cancelling print 4 because I was concerned it would be too big but then printed it again to see the overall structure with the supports before scaling down. This attempt printed but the support material was almost impossible to remove. I spent a long time trying to carefully remove it only to break two of the four rings in the process.
Iteration 4: Instead of laying the ring flat on the bed, I oriented it so it was standing vertically. This way the supports would help in building the vertical layers but not fuse the rings together. This worked so much better with a sample print and then I was able to print scaled versions for the gum ball capsules.
PLA:yes :yesOriginal Prusa i3 MK3(S/S+) 0.25 mm 210 C 01:21:25 65 C 3,284 m. 9,80 g.
Overall, for this design FDM wasn’t an ideal printing method as there was a lot of support material required for the print and due to the geometry it was easy to accidentally break the print while removing the supports.
Moving over to SLA I used both the FormLabs printer and the Prusa. The Prusa was a little faster than the FormLabs printer but both were faster than FDM. Additionally, there was much less support material required and it was very easy to remove after cleaning and before curing. For this print, I much preferred the overall finish texture of SLA as well because the curves were smooth as opposed to the gaps around the top layer of the print with FDM.
Cost SLA: $1.15 total material used (successes and failures) 10.8 hrs print time @ $1/hr = $10.80 2 hrs setup and troubleshooting @ 7.25/hr = $14.50 1 hr post processing = @ 7.25/hr = $7.25 Total = $32 Cost SLA ~$1.52 total material used 3.5 hrs print time @ $1/hr = $3.5 0.5 hrs setup/post processing @ 7.25/hr = $3.63 Total = $8.65
