My Contribution to the Project – FarmBot “Sipmate”
During the mechanical engineering week, our team built a FarmBot in the lab – the Sipmate. This bot is mechanically based on a 3D printer system with three axes (X, Y, Z), controlled by stepper motors. Instead of a heated nozzle, water is dispensed via a hose to irrigate plants. A second head can also dispense seeds, helping to simplify planting in the spring – especially useful since regular watering is often forgotten.
To make the project not only functional but also popular in the lab, we made the design modular: It also allows us to fill shot glasses (“Pinnchen”) – a playful contribution to the after-work culture in the lab.
Together, we planned the machine, created prototypes, and assembled the final product. The preparation, testing phases, and close coordination within the team were crucial for success.
1. 2D Design
1.1 Inlay Tests
I focused intensively on designing the inlays that would hold both the plant pots and the shot glasses. Initially, we created a rough frame out of cardboard to estimate the size proportions. After switching to aluminum profiles, I measured the inner areas and lasered several inlay variants from cardboard to find the best solution, always with a focus on sustainability and material efficiency.
It turned out that the first variant (hanging over the edge of the profiles) was impractical. After discussing it with the team, we opted for the second variant, where the inlay fits between the profiles.
To bring the holder to the exact height, I collaborated with our 3D printing expert, who designed custom supports, which I then screwed into the T-slot nuts – honestly, I don’t want to see T-slot nuts for a while!
I then laser-cut the final version of the plates, considering the required diameters and height specifications. The plant pots were easy, but the shot glasses required testing different heights since they are tapered.
After discussing with the team, we found the optimal height to minimize any movement – ensuring nothing spills.
1.2 Modularity and Adjustments
During development, new challenges arose: The bottles needed to be securely fastened, and the axis was blocking access to the rear holders.
I acted quickly by moving the holders further forward and incorporating the bottles into the “wet compartment.”
Since I was working with parametric designs, I was able to implement the adjustments efficiently. My previously created plate converter was extremely helpful in this process.
1.3 Lasercutting & Thermoforming
The machine also needed a catch basin for excess water. I solved this by creating a thermoforming mold: I lasered several positive shapes from cardboard, with holes in them. The holes help during the thermoforming process by ensuring the plastic plate is sucked down evenly.
I glued the cardboard layers together and then heated the plastic plate in the thermoforming machine. Once it reached the right temperature, I pressed the mold from below and activated the vacuum to create the suction effect.
After a brief cooling period, I was able to remove the cardboard mold without issues.
Finally, I cut the formed plate to the correct size and smoothed the edges.
1.4 Side and Rear Walls
Next, I focused on the external walls of the system. The rear wall needed to separate the electronics from the wet watering compartment, so I cut openings for the DIN rail, power supply, and pump into the acrylic plate.
Initially, I attached the walls using the DIN rail, securing them with just one screw at the top and bottom.
However, since the frame quickly warped, Julian later designed stable 3-screw connectors, which meant I had to rework the plates and laser them again – requiring high precision in the laser cutter.
I also made sure the side walls remained transparent so the plants could receive light from multiple directions.
Additionally, I paid attention to leaving a small gap at the bottom of each plate to prevent them from dragging on the floor when moving the machine.
1.5 Cabel protection
For the display cables, I laser-cut a custom acrylic plate and engraved precise bend lines to ensure accurate folding later on. In the FabLab, I used our bending machine, which heats the acrylic with a hot wire, allowing me to make clean and accurate bends exactly where needed.
Afterwards, I mounted the cable guard onto the side profile using T-slot nuts, ensuring the cables are neatly routed and securely held in place.
2. 3D – Collaboration & Construction
In the 3D area, I initially attempted to make tests for building an olive chute for the machine. I measured the sizes of the olives and tested various angles. Unfortunately, we later realized that the available space was too tight, so I had to abandon the Martini olive idea.
Instead, I designed a lid for the bottle attachment, adapting it to fit the bottle’s threading. Later on, as the machine’s mechanical performance evolved, I adjusted several existing designs based on our findings. More on that in the next section about debugging.
3. Debugging – Testing, Recognizing, Adjusting
During the assembly, especially toward the end, we discovered some mechanical issues. The side walls were slanted. The angles we had attached at the top created a gap between the frame and the plate. To straighten it, I shortened the existing angles from Julian and adjusted them so that they compensated for the gap at the bottom of the frame.
Next, we noticed that the side stop of the Y-axis was blocking the Z-axis slider, so the heads couldn’t move up properly. I made the necessary adjustments to resolve this.
We also encountered issues with the display. It was mounted on brackets that were screwed into the profiles. Unfortunately, these brackets weren’t press-fit, and the display wobbled and fell off with the slightest touch. I thickened the brackets and adjusted them so that they could be 3D-printed in a way that provided a secure and stable mount for the display.
We discovered that the Z-axis was causing some issues with the heads Lars created. To address this, I modified the file for the metal sheet he designed and re-lasered it.
5. Additional Hands-On Tasks
Alongside all these tasks, I also took on several hands-on responsibilities typical in a maker project:
I did a lot of soldering, metalworking, and used the angle grinder (flex) as needed during the setup and fine-tuning of our machine.
What I Learned
This project clearly showed me how essential close teamwork is – especially when working on a modular system with many interfaces. Each part needs to work not only independently but also in harmony with other components.
Through intensive coordination, we learned from each other and complemented each other’s knowledge – I gained a lot of expertise in 3D printing, construction, laser cutting, and mechanical stress.
In the end, it wasn’t just the technology that mattered: The shared power nap after a long day of building also helped to strengthen our team. When you sweat, laugh, and tinker together – that’s when you know you’ve done it right.
“If you’d like to see the owl process from my group, check out this link: our group website
files
3D printing files
distance_plate_cornerbracket_backside_left
distance_plate_cornerbracket_backside_right
2D lasercutting files