Drawing a picture with nearly perfect symmetry can be a tough feat. It requires endless patience, rulers and other graphing tools, and a steady hand. YouTuber JBVCreative set out to automate this process by constructing his own machine that can draw patterns automatically.
The brain of this device is a simple Arduino board with Bluetooth connectivity. It talks to an app that gives it various parameters, including the turntable speed, oscillation rates, and where to position the marker. A pair of L298N motor drivers provide power and control for the three DC motors that comprise the table and both arms. This machine is mostly made up of 3D-printed parts, as nearly everything except the table's top is composed of PLA plastic.
As stated before, nearly every single component is 3D-printed. The base contains two geared DC motors, and they each rotate a slotted horn around. From there, the primary arm is attached at two points that allow it to slide and rotate. Next, the rack and pinion assembly is added onto the top, and it moves the marker in a purely linear fashion. Finally, the turntable is just a motor that spins a platform around, and it is on there that the paper rests.
This device is a member of a family of machines called spirographs. They work by spinning a platter underneath some kind of drawing utensil. This machine has another degree of freedom in the length of the arm, which moves the marker closer or further away from the center. The two motors in the base each oscillate the arm in a certain way, and changes made to the frequency of either motor can drastically change what the final result looks like. There is also a servo motor that is responsible for raising and lowering the marker. These five degrees of motion together produce some very mesmerizing patterns and shapes.
The app that controls the machine has a slider for each rotational axis and an increase in its value will cause the motor to move at a faster rate. It has buttons for raising/lowering the maker and stopping the drawing process once finished.
Initially, JBVCreative set the rotation speeds for each axis to about the same rate, which resulted in a drawing like this:
He also tried setting one DC motor to move very slowly, and this produced a very odd looking pattern:
This project is a very good showcase of how a simple principle and device can create intriguing works of art through basic operations. In the future, JBVCreative should revisit this project and perhaps add a few more features, such as a design preview in the app or a mechanism to automatically swap colors.