Color Mixing Spray Paint On The Fly
One of the problems with being a graffiti artist is that you have to carry around a different spray can for each color you intend to use. [Sandesh Manik] decided to solve this problem by building a rig that can produce a wider range of colors by mixing the paint from several cans at once. Check it out in the video below.
The project is called Spectrum. It uses four off-the-shelf spray paint cans—colored red, blue, yellow, and white—and mixes them to create a wider range of colors. All four cans are hooked up to a single output nozzle via a nest of tubing and a four-to-one tube manifold. Key to controlling the flow of paint is a custom device which [Sandesh] calls the “rotary pinch valve,” with one fitted to the feed line coming from each spray can. These valves use a motor-driven lever to pinch a plastic tube shut, allowing them to control the paint flow. This design keeps the mechanism and paint completely separate, which was important to stop paint from fouling the valves in short order. It also prevents backflow, which keeps the paint going towards the outlet and prevents ugly messes. By quickly actuating the valve, the paint flow from each can is modulated to mix various colors as desired.
The mixing valves are under the command of an Arduino Nano. The microcontroller reads a series of knobs to select the amount of each component color to mix, and displays relevant information on a screen. Then, when a pushbutton is pressed, the valves are actuated to spit out the right amount of each paint from the atomizer nozzle. [Sandesh] went so far as to include an advanced “gradient” mode, where a force-sensitive button allows the device to transition smoothly from one color to another depending on how hard the button is pushed.
It’s a neat concept which we’d love to see explored further, perhaps with a more traditional selection of CMYK paints rather than the more unusual red, yellow, blue, and white. We’ve also seen some fun spray paint projects before, like this neat wall-mount plotter. Video after the break.
youtube.com/embed/IicmGjPu4J0?…
hackaday.com/2026/03/01/color-…
