[Anton Gaia]’s SPIRAL sculpture resembles an organizer or modern shelving unit, but what’s really interesting is how it goes together. It’s made entirely from assembling copies of a single component (two, if you count the short ‘end pieces’ as separate) without a fastener in sight. [Anton] made the 3D model available, so check it out for yourself!
The ends of each part form a tight, spiral-shaped joint when assembled with its neighbors. Parts connect solely to themselves without any need of fasteners or adhesives.
The end result is secure, scalable, and with a harmonious structure that is very pleasing to look at. Small wonder [Anton] used it as the basis for artistic work. You can see more pictures here.
The design of the joint is based on the golden spiral (which it turns out is also a pretty useful chicken coop architecture.)
The parts lend themselves quite well to 3D printing, and we’d like to take a moment to appreciate that [Anton] shared the .step file instead of just an STL. STEP (or STP) files can be imported meaningfully into CAD programs, making it much easier to incorporate the design into one’s own work. STEP is also supported natively in many 3D printer slicers, so there’s no need to convert formats just to print them.
A brief video describing SPIRAL is embedded just below, with a closer look at how the pieces fit together.
I wonder if you could use this for creating mazes for robots / small critters to explore?
ferb, I know what we’re doing today
So if a ~270° spiral gets you a 90° angle, could you use similar explementary geometry to get triangles/pentagons/hexagons etc.? I’m AFP (away from printer) right now and can’t try it though I’d imagine material thickness would need to be considered.
It’s not the 270 degree’s that counts, It’s the ratio between the angle and the diameter with the wall thickness. I.e. this has 4x the material thickness in 360 degrees, and thus four lobes. This also had nothing to do with the “golden spiral” (which is logarithmic). because of the constant diameter increase with angle, it’s much closer to Archimedes” spiral. (xkcd/386)
Yeah, I bet if the “exit angle” was 210 and you changed the thickness to plan for three plates it should make hexes.
Surely it has to be 240 degrees to make hexagons. 210 is nothing, that would just fall apart.
If each spiral had a base plate for its 90 degrees, it would create a box to store parts in.
I printed the pieces and one thing that became apparent after handling and assembling them is that the joint is (sort of) self-tightening, in a way. The curved ends of each piece can be pried “outward” a little to increase the space between them and ease assembly, but once the pieces are together, they all sort of clench onto one another as they return to their original shape — making a tight knot of a spiral in the process. It’s pretty neat.