A set of various sized alternate detergent bottle caps. Should cover most of the available brands in central europe and hopefully beyond.
The XXS Cap has a threading facing the outside and only fits the large Ariel (100 washs) bottles. The XS to XXL versions fit most other (~95%) of the available bottles. For some (transparent bottles for the most part) you might need to slighty decrease the size in the slicer to make them fit (S and XS versions).

Recommended 3d printing settings:
3 shells, at least 25% infill (we used 40%) and with a brim (to increase the connection to the build plate). No supports needed.

Filament considerations:
As we are planning to set up the structures several times and during the hot season outside, we decided on using recycled ABSx filament from nobufil, a local company in Austria, just outside of Vienna. If you are deciding to use ABS, don’t forget to check the shrinkage of your filament before printing and scale the caps by that value in your slicer. Otherwise the standard 25mm PVC pipes (we recommend using) will not fit.
We believe PET-G will also work. Especially if you are not planning to use it for extended periods outside under harsh conditions (UV exposure).
PLA might work, but for depending on the size of your structure we wouldn’t recommend it at all as they have to transfer structural loads. PLA is very brittle and especially not an option if you are planning to build outside.

file format: individual zip files containing an .OBJ + .MTL (nurbs) and a .STL (mesh) version of each cap.