Intro:

For this project I chose the proficient level challenge as I already had experience with 3D printing and CAD from my ENGI 120 project. I used shapes available on TinkerCAD to design my object. I also subsequently posted my design on Thingiverse.

For my design I decided to create an Icosahedron trapped inside of the frame of a cube. This is an “impossible object” as it must be created by building the icosahedron inside of the frame as it is impossible to extract without breaking the object, which is made possible by the layer-by-layer building process of 3D printing.

The Process:

Labor: About 15 minutes of TinkerCAD to create the object, about 1 hour of setting up prints and waiting at the OEDK.

SLA Process: Formlabs Form2

Time to make: About 3.5 hours to print, plus 30 minutes to wash and cure for the 6 Impossible Icosahedron .stl file.

Cost: ($2.30 – $3.12 per cubic inch)*(3.26 cubic inches – Found using Solidworks) = ($7.50-$10.17) for the 6 objects

FDM Process: Prusa i3 Mk3

Time to make: 46 minutes for the single object, 4 hr 38 min for 6.

Cost: $0.12 for each object, $0.72 for 6 objects

Closing Thoughts: The main differences I found between the FDM and SLA final products are the minor imperfections on the objects. The SLA print needed to use an excessive amount of supports, which after tearing off left nubs and markings on the final product. Meanwhile the FDM print which did not use supports was somewhat stringy as some of the filament could not hold in it’s horizontal positioning. I also had trouble starting some prints on the Prusa printers as the first layer would not stick, so I had to attempt to print multiple times before some prints would succeed.