The 3D printed parts were designed in a combination of FreeCAD (for the transparent curved parts) and OpenSCAD (for the base & cap parts), because I find OpenSCAD to be a better tool for doing repeated hole patterns, but FreeCAD was better for creating the spline shape of the LED holders. OpenSCAD and FreeCAD are both free and open source programs that run on Windows, Mac, and Linux.
You'll need to print a total of 12 of the LED guides in transparent plastic. I chose PETG, but because as LEDs do not give off much heat, PLA or other types of plastic should be fine. It's important that the LED guides be printed in a transparent or translucent plastic.
I used my slicer's "fuzzy skin" setting to increase the diffusion effect. The LED guides do not need support.
If you have a 210mm or larger bed, the STL file mult.stl has 4 copies of the LED guide, so you would need to print it 3 times. Otherwise, splinelamp-v4-Body.stl contains one copy and needs to be printed 12 times.
The remaining 3 parts need one copy each: There's a top, a bottom, and a middle part. The top and middle parts do need support on build plate only. Flip the side with the hexagonal 'holes' down on the build plate. Make sure to turn off the "fuzzy skin" mode if you used it earlier. I printed these in white, but you could use other colors or even make these out of transparent filament too.
The file plated.stl has these three parts in their correct orientation.
You can print these files with whatever color & material suits you.
To modify the parts, download the design (.FCstd and .scad) files using the button below:
Also seen in the cover photo: 5 Tetrahedrons in a Dodecahedron by Kristian_Laholm