Idea 095a - Light Graffiti Projector

1 minute read

This post is part of the 100 project ideas project. #The100DayProject. I am looking for feedback. Comment below or DM me via social media Instagram, Twitter.

One Line Pitch

Cheap and easy way of projecting a message onto a building


A light projector is a way to post your message on a building or wall without damaging the property. This can be useful when you are in a protest or just want to get your message across.

You could use a video projector but they are expensive, use a lot of power. We are looking for something we can set up and leave it where it is.

Parts list

  • A cheapo plastic lens from aliexpress ($1-2)
  • Two cardboard tubes - one that can fit inside of each other. It doesn’t need to be perfect. I have used ABS piping before
  • Either a high powered flashlight or a 1-2W LED with a battery

Create stencil the traditional way with a x-acto knife or use a laser cutter to make something with more details.

Attach the stencil to the outside tube, put the flashlight in the tube, bring the flashlight backwards and forwards in the tube until it focuses properly.

Think of a cheap overhead projector.


  • Find some way of letting people know this is not a bomb. Especially if you don’t use a flashlight and there are wires leading to a big battery.

Prior art

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