I could spend hours on the Thingiverse website. I ultimately narrowed my options down to a few different articulated figurines. This tiny articulated robot was my first choice, but other users’ comments revealed many problems with printing. Instead, I chose the Rock head slug, which combined two highly reviewed models. I loved the movement of the articulated slug body, and I thought the Rock’s head added a funny touch.

Using Rhino, I scaled the STL file down to fit into the small pod. I printed multiple test sizes on the FDM printer at 6mm, 9mm, and 11mm. The articulated body could curl to fit, but I was worried about the size of the Rock’s large bald head. The 11mm slug was able to fit perfectly when the neck was arched backwards. I used automated tree supports and printed my three final slugs in white PLA filament on the Bambu printers.

Testing slug scaling sizes

While the FDM printing went smoothly, the same can not be said for SLA using the Formlab printers. I printed two slugs in clear v4.1 resin, then washed them for 5 minutes in the automated bath. I then cured my prints for 30 minutes at 60 degrees. After removing the supports, the slugs stayed horizontal and rigid. The curing process solidified the resin jointstogether. I decided to reprint my SLA prints following Professor Bisesti’s advice to use an air compressor before curing.

The printer malfunctioning

While printing my final resin slugs, the Formlabs printer stopped mid-print. I closed the vent, removed the cartridge, andsqueezed the bite valve to ensure it wasn’t clogged. I also cleaned the metal sensor to ensure the issue wasn’t in the connection between the printer and the cartridge. After troubleshooting and placing the cartridge back in, the printer still would not run properly. I eventually had to abort my print and join the queue for the other printer, since we concluded that the cartridge ran out of resin and we did not have access to the replacement cartridges.

Slugs curing for 30 min at 60°C

Showing off the articulated joints of the resin print!

Down to one printer for all students, I had to come back the next morning to post-process. I washed my slugs, then blasted them with the air compressor, focusing on the connection joints. I then let them air dry for around two hours before curing them. Finally, I removed the supports with clippers and tweezers and carefully bent my joints. The resin prints were articulated using the new technique, but they were still not as mobile as the FDM printed slugs. I tried using sandpaper to post-process my prints, but I did not like the effect it left. My Rocks have some grit to them, just like the man himself.

It fits!

A final slug

Cost Breakdown:

Materials:

PLA filament $32.99 for 1000g -> 6 prints (including trials) at approx. 15g each = $2.97

Clear V4.1 Resin $159 for 1L -> 4 prints at approx. 15g each = $7.95

1 month of Makerspace = $50

Labor: 7 hours (mostly waiting and troubleshooting the machines) at $15/hour = $105

Total = $165.92