I chose a bottom to top approach for my construction. Because of the lack of time for finishing the construction in three days, I decided to start with the smallest elements of the construction and then go bigger and bigger.
I had to implement a flexible rotatable joint for the tubs. For this reason I started with one bar and added the first joint.
Between the nut and the screw head I placed a distance piece. This distance piece was an old heating pipe (top left picture). I polished the ends so that the friction is minimized. Additionally, I put a second nut at the end of the first nut, and twisted them against each other. This a common approach (top right picture) that the first nuts does not get lost after many rotatations.
The rotation worked really well even without any additional weight of a tub. During testing by hand I reallized that I drilled the holes on the wrong way. But at the end I figured out that the stupid fail has a much better leverage impact than what I planned before. So sometimes failure becomes a feature ;-)
Afterwards I created a second bar and melted a prototype suspension. Next step was to implement a good leverage effect for the whole construction. I wanted to lift the construction with a rope hoist. Unfortunately, this approach did not work well because the force was directed vertically. This had no impact to the rotation at all. It is obvious for everyone, who has some really basic knowledge about forces. However, I looked for a solution for get an initial rotation. During practical testing I realized if the construction is lifted around 30-15° than it works fine with a hoist. For this reason, I melted a small lever arm at the top end of the bar.
After testing I had to realize, it works much better but with real weight of the plants, it still won’t be easy to lift. So I improved the construction, but it was not enough.
After some guidance with the teacher it was obvious that the forces had to be routed not directly. We suggested that a triangle ficture should solve this problem. To figure out which is the best position and distance of the 3rd bar I drilled a few more holes in the bar. Afterwards I could really easy experiment with the best measurements. The result was that it was not so important where the 3rd bar was placed on the other bar. The length of the 3rd bar was much more important. During testing I figured out that the 3rd bar should be placed at the last half of the bar and it should be around 1m.
In the end it worked really well and it is now very easy to lift.
Vertical Garden – First Prototype from der hess on Vimeo.