p2:5 – 3D printed RGB LED Sign – assembly
It’s been a long journey, but the final stretch is here. With all the parts printed and the programming done, all that’s left is to assemble everything. Unfortunately, this means a lot of soldering and wiring of LEDs and fishing the wiring through the sign. Tedious yes, but well worth the effort! By far the most difficult part of this assembly was attaching the letters and words together.
body assembly
The pieces each have screw holes placed in join blocks that were designed into the various sections. You can see this above. One side was designed to accept an M2 screw, while the other was designed to fit an M2 nut. I initially considered just screwing into the plastic itself. I actually tested this and it was fairly sturdy. But in the end, I didn’t want to risk the screws tearing up the plastic and coming loose from picking up and moving the sign here and there. In the end, I think having the nuts for the screws to grab onto and keep the pieces tightly together was a better choice and not that much more effort to implement.
There are also wire routing holes, which unless absolutely necessary, turned out to be more of a pain than they were worth. In hindsight, I should have just made open gaps that could be used to route the wires. As long as they weren’t visible from the front or sides, that would have been sufficient. Having the holes embedded deep within the body of each letter made it very difficult to route the wires through, especially with chubby hands like mine.
fitting the letters
After attaching all the letters and words together, it was time to fit the actual letters in the body. The letters were designed to be pressure fit with a fairly small tolerance. I probably could have added more tolerance, but most letters fit in perfectly and any that were a bit too tight were sanded a bit to smooth down the layer lines. In the end, all the letters fit well and looked fantastic.
LEDs and wiring
Wiring up the power and ESP32 also proved to be fairly difficult. I needed to be able to draw power from the USB and split it into the ESP32 and then into the LEDs via a capacitor. I also needed to be able to run the data signals to the other two LED strips. Making sure all these wires fit and could route properly was a bit of a pain in these tight spaces, but I was able to make it happen.
I had originally designed two screw posts to attach the ESP32 at two corners but one of them snapped when I was trying to insert the screw. I suppose the print quality for the small, yet tall screw post wasn’t good enough. Luckily, the single screw post seemed to be sufficient and everything fit fine. The bit of give actually turned out to be a good thing because it allows enough space to plug in a microUSB to update the ESP32 when needed. ESP32 does support over the air updates, but I did not set that up and wasn’t planning to set it up for this project because I don’t foresee having to update it much, if it all, once it’s ready to go. Perhaps a bug fix here and there, but that’s about it.
Due to the size of the letters, I couldn’t simply cut the LED strips to length and wire the different sections. Instead, I had to cut individual LED sections and wire them all together in a serpentine pattern through the letters. I didn’t want to use more LEDs than necessary due to power concerns and I wanted to ensure the LEDs were spread out enough to fully light the letter without obvious dark spots. It created a tedious task, but once I got going, it wasn’t too bad. I also split the task over several days and did a bit when I had some time.
project complete!
I tested the LEDs section by section as I wired them up to ensure there weren’t any issues. But it was smooth sailing for the most part and everything looks fantastic. Assembly complete! In the next and final post, I’ll share pictures of the final product and a video demonstrating all the features.
