Adafruit Forums user aaronaverill has done a wonderful job of designing a NeoPixel jewel/strip to fiber optic attachment:
I wanted to make some fiber optic art effects and props but struggled to figure out how to attach fibers to a Neopixel Jewel or to Neopixel Strips.
I finally designed a working 3d printed fiber to pixel attachment landing on a kind of twist-lock bayonet connector inspired design. The 2-piece design locks the pixel in place, so fibers stay exactly centered over the pixels, and are both durable to bumps without falling off while being removable if you want to reuse the pixels or fibers for another project.The Fusion 360 design is in the link below:
The entire model is parametric, and will probably work for any round or square neopixel PCB from 1 to 7 bits with some minor tweaks. User parameters are listed below, defaults in parenthesis, grouped by general use:
board_diameter – how big is the PCB part of the board (24mm)
board_thickness – PCB thickness (1.2mm)
board_overlap_width – how much overlap to keep PCB in from bottom piece (5mm)
chip_height – how tall is neopixel (1.6mm)
chip_width – how wide is neopixel (4.9mm)
outer_diameter – how big do you want the outer “hex nut” size (40mm)
bottom_thickness – how thick do you want the bottom piece (5mm)
fiber_hole_diameter – hole size (5mm)
fiber_hole_length – hole length (7mm)
wire_width – width of slot for connector wires underneath PCB (10mm)
wire_height – how thick is connector wire (0mm)
fit_spacing – gaps for 3d printing fit tolerance (0.3mm)
tab_width – width of pins (3mm)
wall_thickness – how thick do you want walls (1.5mm)
I’ve printed in PLA and ABS, and the fit tolerances are wide enough to work with quick low quality 0.25 layer height without problems. I’m thinking ninjaflex will work nicely too and be more grabby on the fiber? Gotta find me some.
You can 3d print the fiber holes, or change the model to make the holes slightly smaller than your fiber and use a drill press to get a nicely finished and perfectly circular hole. I’m doing that along with heat shrink tubing around the fiber clusters, along with glue for good measure (into the connector, not the NeoPixel). I designed the model to minimize wasted plastic. You can print with 0% infill and it’s been design to print with no supports for a clean finish (print the top “upside down”)
Feel free to use as-is, modify to add attachment clips or mount holes, hack, etc. Enjoy!
Here is a model with the correct parameters set up to slip over a neopixel strip with IP67 silicone sheath:
This works for this strip that adafruit sells and many others – the 14mm x 4mm sheath seems to be an industry standard:
It’s a bit more fussy than the PCB but still works. Be careful when you tighten it down you don’t tear the silicone. You can also do a quick sand of your 3d printed parts to make sure they are a bit more smooth.