MODUON

The Spark & The Challenge

Back in October 2023, we went on a camping trip using a well-known brand trailer borrowed from a family member—someone very dear to us who sadly passed away in 2025. That trip got us thinking about buying something similar for ourselves.

As an engineer, I was immediately sketching out modifications to tailor a rig to our exact camping style. But the math didn't add up: buying new was prohibitively expensive, and buying second-hand meant paying for features we didn't want while tossing out things we didn't need. Half-joking, I turned to my wife and said, "I can build it better and cheaper."

I wasn't trying to launch a commercial trailer brand—I simply wanted to build one perfect setup for our family.

First Principles: Manufacturability & Materials

My background in CAD and mechanical engineering kicked in immediately. Right off the bat, I established clear design constraints, some of them were:

• CNC-Laser & Press-Brake Friendly: The entire design had to rely on precision laser cutting and standard press-brake bending—no costly custom tool dies.
• Modular over Monocoque: A monocoque design was ruled out. If a panel dented, or if we wanted to redesign an internal layout later, I wanted the ability to unbolt and swap out a single modular component without scrapping the whole rig.
• Ladder Frame Chassis: I opted for a high-strength mild steel ladder frame rather than aluminium. While aluminium saves weight, its susceptibility to structural fatigue cracks under prolonged off-road vibration made mild steel the clear engineering choice for long-term reliability. (I’ll share a detailed weight-comparison breakdown in a future post).
• Matched Vehicle Track Width: The track width had to match popular overlanding tow vehicles—a critical requirement that tightens space for soft-top tent side overhangs.
• Wheels on the trailer and tow vehicle had to interchangeable.
• Have a low tare weight, when the trailer is fully loaded with water and gear it should not exceed 1000 kg.
• High ground clearance for technical trails if needed, low centre of gravity and overall roof height should be low enough to clear standard residential garage doors and reduce highway wind resistance.

The Custom Tent Roadblock

In my early CAD iterations, I designed a quick-setup 270-degree awning along with a custom tent layout to bridge the classic gap where rain leaks in between rooftop tents and awnings. However, getting quotes for custom tent manufacturing hit a brick wall—custom canvas work cost more than double the price of off-the-shelf units from established manufacturers.

I briefly considered sewing and building my own tent, but sanity prevailed: building the trailer and modular boxes was already a massive undertaking. Splitting focus would run the real risk of leaving the project half-finished. I went back to the drawing board, redesigning the top platform (around 2.2m x 1.5m) to universally accept off-the-shelf clamshells, roofracks, or soft-top tents.

The Evolution (2 Years of Iterations) CAD modeling is only 10% of the design phase; the rest is Finite Element Analysis (FEA) stress testing, weight distribution math, and endless sourcing calls for axles, heavy-duty slides, locks, cable routing, and fridge dimensions to name a few.

13 Months Later: Exaggerated side-angle iterations. The side angles if not exaggerated as in the picture below is visually appealing and due to where the hinges are mounted when you open the door they naturally stay in the open position which is nice, but not when you want to open the door a bit to grab something or can't fully open the door e.g. when accessing from the inside the drop down tent may be in the way. You end up fighting with a door and a simple solution is to add a gus strut.

18 Months Later: Tested a curved nose cone. While visually striking, but it created unusable internal "dead space" on top and inside.

24 Months Later: I flattened the nose cone profile—maximizing internal storage while leaving top-deck space for firewood. I also decided not to add jerry cans and jerry can holders to the trailer - the trailer does not need the fuel and if needed it will be packed with the vehicle. Although there is space if you want to add it to the trailer.

The Real Support System Behind every late-night CAD session, stress calculation, and weekend spent away in the shop was my wife. She endured endless hours without me and stepped up around the house so I could keep my focus locked on completing the build. Without her patience and support, this project would have stayed on a computer screen.

What started as a single weekend project eventually grew into the Moduon M1—built with patience, refined by geometry, and proven on the road.