This springy double helix lamp was designed for use with the same iNextStation Neon LED ropes and same 12V power supply as my Power T sign. You will have to cut away a good bit of the silicone at the end to make the strand reach inside the base.
Please take caution printing this in PLA as some users have reported that after extended use the coils may begin to warp.
I recommend printing the coil with its axis parallel to the print bed and using supports. Its a pain to remove them afterwards, but unless you really trust your printer's bridging abilities its the best solution I found. The small rectangular piece is to serve as the end cap.
The author marked this model as their own original creation.