Personal Puddle Light

Simple (not so much) way to make a personalized puddle light in the car door in pretty cheap way.

Puddle light

3D printer

Transparent tape

Pick just any cheap one projecting some car logo. Mine cost 12 EUR for a pair. The Audi original cost 500 EUR :) Sure, the Audi have a brighter light but not to compensate the price difference. Just be careful and pick for the correct car (year, facelift) and correct door (left/right, front/back).

Cannot tell you how, each is a bit different. Mine looked impossible to open without a hammer. So, I applied one of the most important rules: If the force is not enough, use more force. And eventually I opened it without braking.

Inside you find part with lenses. Take a picture of it and remember where exactly each of them is. Because, believe me, you will drop the lenses box, and you must put it back after you lose all the lenses on the floor.

Inside the lenses box is one more tiny box with the part we are looking for: GOBO (GOes Before Optics). It is special little filter mostly with logo of some car (Audi in my case).

If you are rich, you can print the Gobo with your design in special shops. In my town (Prague, Czechia), it would cost something like 70 EUR so I was easily convinced I must make it cheaper by myself.

I've got several "great" (really bad) ideas how to make it cheap. All of them wrong so I'll tell you each of them to save your time.

1. First bad idea: Scratch it on some black foil. You can see the result in the picture above. As you can tell, it's fine for halloween, but certainly not usable.
2. Second bad idea: Paint it Big and Make small later. (Seems like a good name for a contest, right). So, I took a balloon, put air inside and painted the design when it was fully inflated. As you noticed, my design is really simple - just MK letters. And even so, the result was so terrible I didn't take the picture just to be sure the ugliness doesn't break my camera. When the ballon lost the air, the painted part was scrambled all over because of the paint.
3. Third bad idea: Paint it with hand. You are laughing hard already; I don't blame you. I have a pretty steady hand, but you just cannot paint anything that is six millimeters wide.

We are living in 3D printing decade, and it was my last idea. How sad of me. I consider myself as tech enthusiast and can't think of the 3D printing?

To my defense, it wasn't as simple as it seems. The whole Gobo circle is about 9 millimeters in diameter. And thickness is close to zero: exactly 0.12 millimeters.

3D print anything that small is simply hard. At least for the guy who printed it for me. He was so nice to print a lot of versions with different diameters and thickness, so I could elaborate the best one.

He even tried multiple thicknesses, each of them just wasn't perfect. There were still a tiny wholes in multiple places around the letters where it shouldn't be. It made quite ugly result. The solution was to spray it with black color spray. The color filled tiny holes and kept the letters.

When you have your 3D printed "Gobo" you need to put it inside the box. I couldn't use the one that was 9 mm wide as original because it wouldn't fit with its thickness. So, I put smaller "Gobo" to a transparent tape and put it there on the tape.

When you assemble the lenses back in correct positions and assemble the light it's time to replace it in the car.

It is not nice work, because under the door is not much space, you don't see there easily. Especially when you do it in the night before Christmas, laying on the street with shitty torch and you are accused from some random walker that you are stealing the car. Trust me, I've tried.

In my car (Audi A4, 2020) the light holds there without any screws. It's just pushed inside the bottom of the door. So again, when I was really desperate and convinced, I will not have the one and only Christmas present for my wife, because I was sure some crazy guy in factory glued it there, I used more force, and it popped out.

Also, it completely felled apart beyond repair. It gave me quite adrenaline because it didn't seem like best Christmas present. Just imagine it: Honey, I have a unique present for you: Broken door with the hole. I made it with love, just use this shitty torch instead if you don't want to step in the puddle.

Thanks to my gained adrenaline and the golden rule (use more force) I putted back the replacement light (check the correct wiring polarity). And it worked like a charm and still working after six months in the car.

As a present it was perfect. Even so long after Christmas there are still tears in the eyes. My wife have them from so romantic present (MK are her initials) and I from some shit that felled in the eye when I was laying on the street tearing down the door.

It is best visible in the night, but it also works during the day, so even cheap light can work.

Maybe you noticed that the MK letters are not centered and are a bit down. Well yeah, it's not perfect and to save it in the eyes of my wife I said it's her halo for all the love she is giving to me and my son.

I am writing this instructable for the Big and Small Contest. I don't want to influence the jury (a lot), but we all know who should get the prize. Right now, this is the only entry, which is Big and Small at the same time! The Gobo is 9mm wide and makes about 80cm big image. Again, I don't want to influence the jury, but everybody sees it's a prize worthy miracle.