Written as inner-dialogue:
There is a problem which is blocking progress for the project. What is the problem?
I need to make vertical columns / tubes via an entirely autonomous machine-driven process. Its not clear how to accomplish this.
What does the machine look like?
The machine shouldn’t be visible, or rather it should be as invisible as possible. All that is seen is a valve that extrudes the substrate (a thick, grainy gel made from starch, compost, sand, and grass seeds). This extrusion-valve gradually rotates and rises resulting in a spiraling column of the substrate.
Doesn’t sound too hard.
There is an easy way and a difficult way. The easy way is simply a long rotating screw with one end in a reservoir of the substrate gel. The rotation creates a type of Archimedes screw which is a simple and effective mechanical device for lifting liquids and gels. As the extruded material solidifies and dries it creates a tube up which more material can be moved. The only additional mechanical movement required is to push the screw upwards in order to grow the height of the substrate tube.
The difficulty arrives when I try to hide the potential height of the tube i.e. the screw is not poking out the bottom of the installation platform. There are several ideas that I have in mind – collapsable tubes, various pressure systems, a complicated mechanical system – but nothing spring out at me yet as the answer I am looking for.