I couldn't find icicles I liked to use in my lightshow, so I remixed this one. I flattened the back, added holes for five 12mm bullet node WS2811 pixels and designed mounting clips to hang them from the J-channel I have permanently mounted along my roofline.

I also made adapter shims for a 4-12 peak, both right and left hanging. The shims have an adapter clip that hold them securely to the top of each icicle, and then hang using the same mounting clips. They have alignment tabs that match up with the icicles to help hold them in place.

Icicles were designed to be printed with a 0.4mm nozzle, 0.2mm layers, 1 wall, 2 top/bottom layers and 100% infill. You can get away with less infill, but I found it didn't print much slower. The infill is only in the base where it mount. The rest of the icicle is hollow, and is only 0.8mm thick. It will print without support when printed with the point up.

The adapter shims should be printed as they appear with the same settings as the icicles. They will print without support.

The clips should be printed at 0.2mm layer height, 4 walls, 4 top/bottom layers and at least 25% infill. Depending on your slicer settings, to avoid gaps, it may be better to print 2 or 3 walls with 100% infill.

PETG should be used for outdoor use. I found I liked the white better than the clear I tried. With clear, you can see each individual pixel. I prefer the diffused look of the white. Although the clear looks better during the day, since it shimmers a bit like a real icicle.

I may create shims for different roof pitches if there's interest.

1/11/24 Update:

Added Icicle v5 - added 2mm hole to tip to allow water to drain
Modified Mount Clip 2 - v2 has relocated the smaller tab that holds inside the icicle to allow the clip to hold better
Added versions of Clip 1 and Clip 2 v2 to include Wire Hooks.

2/8/2024 Update:

Added 2 new mounting clips with a revised wire hook. One clip has been modified to tilt the icicle forward about 7.5 degrees, as I found my J-channel was producing a backward tilt. This should allow my icicles to hang straighter. I have not printed the tilted version yet, but will update when I verify their function.

Planned Modifications:
Longer version with true 2" spaced pixels
7 pixel version - will also be 2" spaced

Tinkercad Links:
https://www.tinkercad.com/things/0WluJHn4nGE-pixel-icicles-public-access
https://www.tinkercad.com/things/9YL6pwiApWy-icicle-mount-clip-1
https://www.tinkercad.com/things/9CUvi6SXtIy-icicle-mount-clip-2-v2
https://www.tinkercad.com/things/49vuOquzd0g-icicle-mount-clip-1-w-wire-hook
https://www.tinkercad.com/things/7XrPpnjkcE8-icicle-mount-clip-2-v2-w-wire-hook
https://www.tinkercad.com/things/czmdkCzAp8y-icicle-adapter-clip