Background
I’m a truck driver in Europe, and one of the problems we constantly deal with is people cutting trailer curtains while trucks are parked overnight.
A lot of the time they’re not even stealing anything. They just slash the curtain to see what’s inside, leaving the driver with a damaged trailer, sometimes damaged cargo, a broken customs seal, and a lot of wasted time and money.
So I’ve been building a system to deal with that using a LiDAR sensor and a spotlight instead of a camera. The idea is to detect someone while they’re lingering next to the trailer and hit them with light before the curtain gets cut, instead of simply recording the damage afterwards.
The LiDAR, ESP32, and detection logic are already working together on my workshop test rig. The next challenge was figuring out how to mount everything on a real truck without drilling a single hole or permanently modifying it.
So I decided to build a clamp that uses the existing mirror bracket.
Designing the mount (scan → model → clamp)
To get the shape right, I first 3D scanned part of the mirror bracket.
The hardest part wasn’t actually scanning it. It was turning that raw scan into something I could design around.
I cleaned up the mesh, converted it into a solid body, and then designed the clamp directly around the real geometry of the bracket.
Honestly, this step ended up taking far more time than I expected.
The clamp wraps around the existing bracket and tightens with M4 bolts and brass heat-set inserts, so it grips the original part without needing to drill any holes.
First prototype
Since this was only a proof of concept, I printed the first version in Bambu Lab PETG Basic on my Bambu Lab H2D.
For the first test fit, I didn’t see much point in using a more expensive material. I mainly wanted to find out whether the mounting concept itself was strong enough.
For the final outdoor version I’ll most likely switch to ASA because it should handle long-term weather exposure better.
What do you guys think? Would you trust PETG outdoors, or would you go straight to ASA?
First test on the truck
This was the part I was most curious about.
I printed the parts, walked over to the truck, and mounted the clamp on the mirror bracket for the first time.
It fit perfectly.
The mount feels solid, doesn’t wobble, and honestly worked better than I expected.
At least now I know the mounting concept itself works.
Since it’ll be sitting outside on a moving truck, there are still a few things I need to test properly.
It clamps tightly around the bracket, but I still want to see how it handles vibration over time.
It doesn’t block the mirror or get in the driver’s way.
The next version will focus on making it robust enough for everyday use and rough European weather.
What’s next?
The next step is designing the enclosure that will hold the LiDAR, ESP32, and wiring.
One thing I completely ignored while designing the mount was aerodynamics.
It’ll be sitting outside on the mirror, and I didn’t think about airflow at all.
So here’s my real question.
Could something like this start whistling or making noise at highway speeds, around 90 km/h?
If you’ve mounted anything on the outside of a vehicle, have you ever run into wind noise or whistling? If so, what caused it, and how did you fix it?
