Tensegrity hexagons

Tensegrity Hexagons.

Tensegrity is a structural principle where elements under compression do not touch each other. They're are only connected and hold in place by tensioned members (usually cables). The term "tensegrity" is short for "tensional integrity and was proposed by Buckminster Fuller in the 1960s.

This experimental model is a study on fabricating such a tensegrity structure. The boundary conditions are set to avoid assembly of the members and making additional support material obsolete. The focus here is on FFF/FDM as fabrication method. The intertwined hexagonal rings are only connected through fine strands to each other for stabilization. They're just filament extruded into the air. This technique is called bridging.

Geometry was created using Rhino/Grasshopper.

Printer: Generic FDM/FFF
Rafts: No
Supports: No
Resolution: 0.2 mm
Infill: 20
Filament brand: Spidermaker
Filament color: Iron Blue, Wasabi Green
Filament material: Matte PLA

Notes:

The model is stable but somewhat fragile, so handle with care during the process.

Note: There's a 3mf-file included with a complete setup ready to print.

The model is split into two files:
1 - rings and base
2 - strands

The orientation of the geometry is as it is layed out in the stl files.

You have to combine them first in your slicer-software (PrusaSlicer or Cura recommended). You can go for a multicolor print if you wish to, but the separation has one advantage in general (even if you're doing only one color). For better explanation have a look at the included picture of the slicing process:

If you're just combining the models and the settings for each model are identical, the extrusion of the strands will end at the perimeter of the rings (A). However, if you change e.g. the number of perimeters for model #2 (which btw has no effect on the strands), it will reach into the rings beyond the perimeter. This also results in a continous extrusion and leads to a better connection (B). This behaviour was tested in PrusaSlicer 2.3.0, it might be different for your slicer software.

Supports are not necessary. There are some spots in the rings which tend to sag a little bit, but it shouldn't be that bad. If you wish to, you can still turn on supports. Bare in mind that removing supports on this model might be near to impossible without breaking it. Soluble supports might be the better option here.

Activating "thin walls" will help with the detection of the strands.

Clean you print surface and ensure good adhesion.