Custom-Built Spray Paint Machine Creates Any Color You Want, Right When You Need It

Carrying dozens of spray paint cans for a single mural is about to become a thing of the past. Mechatronics student Sandesh Manik has built Spectrum, a compact machine that transforms four standard spray cans into hundreds of custom colors on demand through ingenious engineering.

The device solves a puzzle that stumped Manik for years: how to blend different pressurized cans without creating leaks and backpressure. His breakthrough came through rapid pulsing valves that open one at a time, sending quick bursts of each color down a tiny one-millimeter tube where turbulence mixes them perfectly before reaching the nozzle.

The real innovation lies in custom rotational pinch valves that squeeze silicone tubes rather than touching the paint directly, preventing the clogs that plague standard systems. An Arduino brain calculates precise pulse lengths based on four knobs on the handle, while a pressure-sensitive trigger lets artists shift color gradients simply by squeezing harder.

Built entirely in a home workshop for under $150, Spectrum gives spray artists the freedom to create any shade instantly without stopping to swap cans or pre-mix batches.