Ramiel-inspired Christmas tree decoration using flexible LED filament

thingiverse

A Christmas ornament inspired by Ramiel from Neon Genesis Evangelion. Uses a 300mm flexible LED filament with 2mm diameter, which seems to be default. you can buy it on Aliexpress, I used that one: https://www.aliexpress.com/item/1005004500671003.html?spm=a2g0o.order_list.order_list_main.24.177e1802Ea8mubThe LED filament does not have a built-in series resistor, neither does the model have room for one. Locating the resistor in the USB plug makes it easier to change if you would like to change the brightness. I used a 47Ω 0.25W resistor.The LED filament seems to be immune to any form of glue, unless you use completely unsightly, massive lumps of it that surround the LED filament. This is why this model has little holes that can be used to tie the LED filament down with a thin wire-wrapping (bodge) wire, magnet wire or fishing line. It is more sturdy and less ugly that way. But it probably requires a resin printer for that reason. Clear resin prints are also a lot clearer than FDM ones.The LED filament bends readily in one plane, with about 1mm radius being still safe (when bending the inner substrate). Bending it in the opposite plane (shearing the substrate) is more difficult and damaging, so you have to twist it along its axis to always bend it in the direction it's more bendable in.The biggest hole lets you tuck the ends of the LED filament in, so they don't show on the outside. You should solder two thin wires to the ends before assembling, as it will be difficult if almost whole thing is wrapped in filament. You should do a test wrap to see how much to tuck in, then do so on the beginning side, putting in the wire from the other side at the same time.