[Ben's] father was a metalworker and the combination of being around metal fabrication for most of his life and getting a couple of art degrees brought together a satisfying combination of hacking skills. Above you can see a Graffiti Machine that he built, which we’ll look at in-depth after the break.. This isn’t the first CNC machine he’s worked on. [Ben] became interested in rapid prototyping but was put off by the cost of commercial cutters, which led him to build his own CNC plasma cutter.
[Ben's] creation consists of a vertical gantry that houses the motors as well as a carriage for the spray paint ‘rattle can’. He’s using stepper motors and belts to move the carriage and gantry with a controller that he picked up from HobbyCNC. Let’s look at how he put it all together.
This is the can carriage. On the right, above the can, you can see the motor used to start and stop the flow of paint. To the left you can see the timing belt used to move the carriage up and down. Its ends are secured with C-clamps.
[Ben] uses the head of a machine screw to depress the valve of the rattle can.
The top of the gantry houses motors to move the gantry itself as well as the can carriage.
The full gantry is one piece with the can carriage traveling along its length. You can see the timing belt that the gears use to move the can.
The two images above show the belts used to move the gantry along the top and bottom horizontal tracks. A rod travels the length of the gantry, driven by a stepper motor on one end to move the gears of both the top and bottom belts.
This image shows the angle-bracket that is used as a track. This gives the machine horizontal scalability.
This closeup shows a skateboard wheel with a slot cut in it. This keeps the gantry firmly seated in the track as it moves.
[Ben] ties the system together with a Linux box running the Enhanced Machine Controller. He’s hoping to pit man against machine some day in a graffiti showdown. This is a great build [Ben], thanks for sharing the details with us.