An interesting light display using 64 Glue sticks and 128 WS2812B RGB LED strips.
This work is based on "Fiber Optic" LED Matrix by jbumstead (https://www.instructables.com/id/Fiber-Optic-LED-Matrix/).
Using OpenSCAD, the goal was to replace the 12mm Diffused Digital RGB LED used in jbumstead's design with cheap WS2812B RGB strips and to make the container for the LED's and electronics as thin as possible allowing cheaper 7mm Glue Sticks to be used.
The only part that requires supports is "Hot Glue Matrix - Bottom.stl". The Top and Bottom LED/glue stick holders have an extra hole to run wires from the bottom to the top section. I used a clear drinking straw to hold the wires (See image). All 128 WS2812B LEDs are wired in series starting at the bottom and finishing at the top. Channels are designed to hold the strips in position and I used blue painters tape to hold them in place once they were wired up.
Just a word of warning, the 7mm glue sticks that you get from eBay are around 100m long. I found that they varied a bit. Mine came in packs of 30 so I had 90 sticks to find 64 of similar length. Also I needed to increase the hole size using a 19/64" drill after printing to make them easier to fit in the holes.
Once you have inserted all the glue sticks in the top and bottom, ensure that the height between the top and bottom sections are the same all away around. Once you have it square, remove the 4 corner ones and super glue them back in place. This makes the structure fairly robust.
Be careful about the orientation of the LED strips. The design only allows the strip to go in one way round (there is space for the small capacitor that sits beside the WS2812B LED). On the top section, DIN starts at the top-to-bottom connection hole. On the bottom section, DOUT finishes at the top-to-bottom connection hole. You need to connect the strips by wiring each strip together. You need to do this off the printed former as you can't connect them while they are upside down. Each strip is spaced 15mm apart from its center. Set up a small jig to do the wiring and then transfer the strips to the former and use tape to hold the LED strips in place. I used wire-wrap wire to connect the strips.
64 - 7mm x 100mm Glue Sticks (ebay)
128 - WS2812B 60 per metre (ip60 non-waterproof)
1 - Arduino Nano
1 - 3A Mini DC-DC step down converter volt regulator
1 - 10K 1/4W 5% resistor
1 - 330R 1/4W 5% resistor
1 - 470uF 10V small profile capacitor
1 - 10K lin 45mm Slider Potentometer (30mm stroke length eg: Bourns PTA3043)
1 - Small push button
1 - Small Rocker Switch
1 - DC power socket (panel version)
1 - Drinking straw to hold wires going from the bottom to the top section.
Eagle files included. I made my board using the toner method. You can just use a piece of proto board if you wish as the schematic is very simplistic and easy to wire up. The 4 mount holes should be drilled out with a 2.5mm drill and tapped with a 3mm tap. I used 6mm M3 screws to hold the board in place.
Work in progress - Test sketch only.
Supports used on Hot Glue Matrix - Bottom.stl only