This is a 10mm grid to fit over a 32x8 LED matrix, as part of a diffuser panel for the LED matrix. As the full 32x8 grid would be too long to fit on some print beds, this was designed to be printed twice, and the two 16x8 parts will fit together.
The squares are spaced on a regular 10mm square grid, their internal size is 9.2mm and the walls between each square are 0.8mm thick.
The LED matrix came from ebay and was described as:
"WS2812B NeoPixel Addressable RGB LED Panel 5050 – 8×32 – 5V"
It looks very similar to these:
adafruit "Flexible 8x32 NeoPixel RGB LED Matrix" (PRODUCT ID: 2294)
Seeedstudio "RGB LED 32x8 Matrix (WS2812B) - 5V DC" (RB-See-420 / SEEED-104990128)
There's a video of the finished article here: https://www.youtube.com/watch?v=ORE7rWveC6Y
Prints upside down to avoid overhangs. This model is designed to print as two identical 16x8 halves (92mm x 164.8mm x 5mm) which can be glued together to form a larger 32x8 matrix. It includes 8 mounting holes which are modelled at 3mm internal diameter, but after printing will end up about 2.6mm diameter. This was designed to fit over a flexible 32x8 LED matrix, and the grid includes clearances for the resistors that sit between the LEDs on the matrix.
The only (subtle) difference between the v08 and v09 files is a small 45 degree chamfer where the grid columns join the grid rows (this was a final tweak before printing).
Displaying digits with paper used as a diffuser.
The same part is printed twice, and rotated 180 degrees to interlock.
Showing the two parts assembled to make the 32x8 matrix.
View of the grid sitting on the LED matrix. It has clearances for the resistors between the LEDs.
Testing with colour ramp and paper diffuser.
Early testing with paper diffuser (it's just resting loosely on the grid, hence a little uneven).
White numerals drawn with 3x5 pixels: comparison with/without the diffuser.
32x8 LED Matrix Diffuser