'String' Together a Work of Art with This String Art Machine

The Idea

Driven by lockdown boredom, YouTuber knezuld11 (Kevin Dluzen) came up with an interesting method for drawing pictures automatically with some colorful string and a bunch of nails. By punching an array of pegs into a piece of perfboard with a robot, intricate designs can be created that look spectacular.

It took a few months to build, but the results are quite impressive.

How It Works

In order to place the nails into their assigned locations, there's a large gantry that moves in three axes: (X, Y, and Z) and uses a custom, geared toolhead that applies enough force to each nail's head and force it into the board below. Then string is taken from one out of a series of thread spools on the side and slowly but surely wound across the entire plane of nails.

Hardware Used

The robot itself is comprised of four different sections: an X axis, a Y axis, a toolhead, and a bank of thread spools. The two linear axes are each driven by a single stepper motor using timing belts and aluminum rods. The primary toolhead is quite complex, and it features an assortment of sensors and actuators, including servo motors, laser distance sensors, and hall-effect sensors.

Generating a Design

In order to actually make something, there must first be a way to come up with a pattern and translate it into an array of both nail locations and interwoven threads. This is accomplished by using a Python program to follow an algorithm/mathematical formula which then outputs two things: nail locations and the path for string to take. A second program uses those two files for input and generates G-code that the Marlin firmware can use to control the motors.

Placing Nails

Nails are first loaded into a small bin that is located within the toolhead. To select a single nail from the others within the container, a platform with a groove for a single nail rises from underneath and pushes one up. A laser-distance sensor ensures that there are enough nails loaded, and if there are, an arm with a couple of magnets attached picks up the nail and holds it upright, where a rod driven by a gear pushes the nail down into the material.

Placing String

The final component in this project is threading string throughout the sea of nails on the board. The machine uses the previously generated GCODE to first grab the correct thread spool cartridge and load it into the toolhead. Then the nozzle is put between two pairs of laser emitters/detectors to calibrate it for differences in the nozzles, which helps to ensure accurate thread placement. A few starting-point nails have double-sided tape on them for the thread to stick.

By using the machine's movements rather than relying on active components to unwind thread and attach it, each thread spool can be easily changed out, enabling complex color patterns to be created.

End Results

The resulting string art is incredible to look at with each piece's intricate layering, spirals, and colors. It is impressive that using a simple formula for fractals can generate shapes with kaleidoscope-like properties.

You can view more of Dluzen's designs at his Etsy shop.