LED Grid Prototype

Take Us to Blinky Town

Usually building an LED Pixel Wall is straight forward. Mount LEDs on a large flat surface, run cabling on the back, connect your controllers and turn it on. Many installations don’t even put diffusers on the LEDs and hit you with raw RGB, which is brighter but misses most of the shades of color.

We have a more unique installation. Recycled plastic bottles act as lenses for 1200 pixels that need to be stacked in a grid against a wall with no access from behind. Cabling needs to connect LEDs to power supplies and PixelPusher controllers.

We initially selected Hint Water bottles due to the pattern on the their base. When running a micrometer around a bottle to dimension it, we found another bonus. The center body of the bottle is slightly smaller than the base and neck. This creates a natural area to clamp the bottle into position and set on us on a design path.

We need two “ribs” with slots cut in them that can be stacked, holding the bottles in place. The ribs need to slide into a frame that locks the whole thing together. After a quick part drawing with two headers, multiple ribs, and two vertical frame pieces, here’s what was drawn.

Cutting file preview

Using a 0.25” straight end mill on 0.75” D3 Maple Plywood eventually results with our parts.

Close-up of one side of bottle slot with tabs

Header and rib slots

Excess material removed on parts

To test the prototype quick assembly with a bottle will check the fit.

Hint Bottle in rib

Test assembly

Three rows assembled

What did we learn?

1. More spacing between bottles would make room for frame currently blocking first and last bottle
2. Bottle slot needs tightened because slop allows bottles to tilt down so lens is not flush with grid surface
3. Using a double rib would make assembling easier since balancing bottles on a single rib is challenging4. 0.5” plywood could support grid of bottles if needed
4. Need a design to prebuild grid sections
5. Side rail slot needs to be tighter - could use aluminum track for finish
6. Practice starting a cutting file from a specific line number
7. Cutting parts the full width of plywood should be avoided until perfectly square alignment of material can be ensured.
8. Our ShopBot Control computer needs upgraded.