Stand for Adafruit LED filament letters etc

When Adafruit introduced LED filament letters earlier this year, I knew I wanted to make a woodworking project that incorporated these to challenge myself to make something that is totally impractical but artistic. 

 I ended up creating the sign shown here. I am super proud of it, imperfect as it is, but the wiring was a ton of work and it was super finicky.  As soon as I finished I realized I needed a solution that was easier and more predictable if I was going to ever work with these again.  What I wanted more than anything was a non-permanent way to add or remove letters from a project quickly and reliably with minimal repetitive effort.  Ideally, you'd be able to create one of those sign boards with the replaceable letters, if you could afford a LOT of filament letters.  

So, while I'm not an expert at anything, I can learn things quickly and am willing to fail, a lot.

Armed with my P1S and Fusion 360 I iterated, and iterated, and iterated…

This model solved pretty much all of the problems I had. You print one per letter and a set of end caps for the whole line. You do need to do one tiny mod to the filament letters.  You need to take the negative connection and wrap a small piece of copper tape around the back, being careful not to connect to the positive side.  This is somewhat tedious but is necessary a successful contact.

So to assemble:

1. Print the first plate for however many letters or numbers you are planning to connect
2. Print the second plate for however many lines you plan to have
3. The first plate consists of a base and a cover
   1. Take the base and place a strip of copper tape (40-45mm) along each side of the inner channel.  Make sure to press the tape tightly around corners using a thin screwdriver or something equally thin and rigid.  Make sure you have enough tape sticking out on both ends to wrap around the sides.
   2. Place the cover on top of the body.
   3. Place your filament letter into the stand, making sure the middle of the letter is in the middle of the stand
   4. Connect your stands by attaching them using the tiny dovetail connectors
4. For each line, attach the plain end cap at the end of your word (L to R languages, start for R to L, but I don't know of filament letters in non-Latin character sets.).
5. For the hollow end cap, you have some choices as to how you wire it up, just make sure the positive power is connected to the inner wall of the cap and has copper tape going out along the rightmost slit when looking at the end.  Negative power should be connected through the leftmost slit. Put a resistor in the circuit to make sure you don't put too much current through the filaments.
6. Hook the power cap to the line of letters and apply power.