In my month of absence, I wasn't just sitting around. I finished implementing the bottom tip mockup in 3D, which required a complete recreation from scratch due to how unsuitable for 3D printing the original model was. I also printed out a second set for a Krystal cosplayer who wanted 3D prints of the two tips. If you want your own set, I'm still offering to print these two tips for $40, plus shipping.
I spent a lot of additional time looking into more lighting solutions. The company who made the prototype Lightpaper never responded. However, I did find that there are that are lots of LED strips theoretically thin enough to use inside a tube with room to spare. It just came down to figuring out which one. I looked at dozens and dozens of options, before settling for now on a 3mm wide strip with 3014 SMD LEDs that are only 10mm apart. The strip is about 1mm thick, well within tolerances, and probably the thinnest you can get without ordering directly from Chinese factories. And bonus, they're cheap too! I managed to get about 32 feet of them for about $50. By my calculations, for the final product, I'll need roughly twice that much, but for now, this is sufficient for testing.
These things are so incredibly small! It's hard to appreciate how small they are using the stock photos on the websites. Check out the strip next to a more normal size LED strip and a normal AA battery.
As for power, though they are 12 volt LEDs, I was able to get them to put out reasonable amounts of light at just over 7 volts. That means I can power an entire strip with just a handful of batteries, if all goes well. The next step will be to create a column of these LEDs around a central core and get that to light up. That will show off what it will look like for the final product. It's not a perfectly even distribution of light, but with a checkerboard pattern and some glass-frosting techniques, I think I can make it appear very even. Below is my tentative setup. I think I'll use a little time this weekend to do some soldering.
The white material below the shaft is some various light transmission and diffusion materials I scrounged from out of dead TVs. Not sure yet if they will be helpful to this project.