2.2 Design a building block - Fabricate

Continue with your 'building block' design. Fabricate it! Make a physical prototype you can try out and test (if you come up with something better or different, you are allowed to, but it might be most interesting to keep the original idea). Document your design (but also the design process: sketches, thoughts, words, mindmap, digital design, production, testing...) in your portfolio!

February 16, 2026
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Process
When I started with this assignment, I had absolutely no idea which material I would use for the LoFi prototype. After some feedback from the teacher, I settled on LEGO. I should also note that even though the prototype is made from LEGO, that does not mean LEGO already has this idea or sells it. I only used the material as a fast way to build and iterate. LEGO is also a very "self-guiding" material (the studs basically teach you how to connect parts), which makes it useful for quick prototyping and trying out ideas without overplanning. This also matches the idea from Invent to Learn that I should get to a first prototype quickly so I can check assumptions and improve through iteration, instead of getting stuck in planning.

Technical hurdle
I wanted to make more out of the prototype, but after spending hours sifting through the LEGO pieces I had, I ended up with a simpler design: one base hub and two modules (see Figure 1). It still gets the idea across, but it did limit how "complete" the system looks.
For the magnetic connection system, I used pins that stick out and go into a hollow block. The idea was: easy connect, easy disconnect, without a hard click. I did try using tighter LEGO pins (black/blue ones), but that made the modules click too strongly, and it was hard to unclick them. Since my original concept was closer to a magnetic feel (similar to littleBits), I intentionally went for a looser click/slide connection instead.
My bedroom while working on the assignment.

Figure 1. My bedroom while working on the assignment.

Context
Figure 2 and 3 & Video 1 - Overview
These figures show the hub, the modules, and how they connect. The video shows the connection in action. Because the design is modular, the order of connecting modules should not matter: the user can choose which module(s) they want and in what sequence.
Try-out / quick test (LoFi): even though the prototype cannot transfer real power/data, I could still test the interaction (what you actually do with your hands):
- whether it is clear where modules should attach,
- whether connecting/disconnecting feels "light" enough,
- whether the modules stay attached when you pick up and move the hub,
- and whether swapping the order of modules still "works" as a concept.
This kind of early feedback-through-doing is exactly why rapid prototyping is useful. You learn faster once you have something physical to handle (and it makes iterating feel much easier, because you can change it right away).

Figure 4, 5, 6, and 7 - Base hub
I started by creating the main hub. The back and side of the hub hold (Figure 6):
- the cable to the laptop on the right side (black rope),
- an extra power input (black chain),
- and a possible internet module at the back.
On the front (Figure 4), I indicated ports/slots: two USB-C (two green pieces), one micro-SD (small grey piece), and one SD card (bigger dark grey piece). I also added a connection light (red piece) to indicate whether the hub is "working," and a screen on top for information (red plate). Having visible feedback is important in making systems easier to understand and "read" while using them.
The connection is done by two one-block extensions (Figure 7), with data/power pins in the middle (I couldn't find the full set of pins I had in mind, so this is simplified).

Figure 8, 9, 10, and 11 - USB module
The second block I made was the USB module. I started with the connection system: since the base hub has extended pins (Figure 7), the module needed a connection that doesn't lock too strongly. After trying different methods (including hard pins), I ended up using hollow 1x1 pieces that slide/click onto the extended part (best seen in Figure 9 and Video 1). This gave the module a more "magnet-like" feel (stable enough to hold, but not so tight that disconnecting becomes annoying).

Figure 12, 13, 14, and 15 - Ethernet module
This module works the same as the USB module in design and connection system (see Figures 13 and 15). Since I cannot make real connections or ports with the LEGO pieces I had, I used a hollow blue block to indicate an Ethernet port (Figure 12). This keeps the prototype focused on the modular idea and the user interaction, instead of pretending the electronics are already solved.
Figure 2. Overall view of the individual hub and modules.
Figure 2. Overall view of the individual hub and modules.
Figure 3. Overall view of the connected hub and modules.
Figure 3. Overall view of the connected hub and modules.
Figure 4. The base hub (front).
Figure 4. The base hub (front).
Figure 5. The base hub (right).
Figure 5. The base hub (right).
Figure 6. The base hub (back).
Figure 6. The base hub (back).
Figure 7. The base hub (left).
Figure 7. The base hub (left).
Figure 8. The USB module (front).
Figure 8. The USB module (front).
Figure 9. The USB module (right).
Figure 9. The USB module (right).
Figure 10. The USB module (back).
Figure 10. The USB module (back).
Figure 11. The USB module (left).
Figure 11. The USB module (left).
Figure 12. The ethernet module (front).
Figure 12. The ethernet module (front).
Figure 13. The ethernet module (right).
Figure 13. The ethernet module (right).
Figure 14. The ethernet module (back).
Figure 14. The ethernet module (back).
Figure 15. The ethernet module (left).
Figure 15. The ethernet module (left).

Video 1. Showcasing the LoFi prototype that I made with LEGO.