Draw Pictures Anywhere with This Portable CNC Plotter Built From DVD Drive Stepper Motors
The P-CNC Plotter looks like a quadruped, but instead of crawling, this device moves a pen across a piece of paper.
The idea for the P-CNC Plotter
Instructables user tuenhidiy had been wanting to build a CNC plotting device for a while but could not find one that required no 3D printing and used very simple, up-cycled components, so they created the P-CNC Plotter. It features three axes that are each independently controlled by a basic Grbl controller shield. This allows it to be hyper-portable and accept a wide variety of drawing toolheads.
Components required
Rather than using expensive and large 3D-printed parts, tuenhidiy went with a series of PVC fittings instead to lower costs. The X and Y axes are each driven by a single NEMA 17 stepper motor and A4988 motor driver board module. The Z axis moves vertically by using a repurposed CD drive slider. Everything plugs into an Arduino Uno R3 and Arduino Grbl CNC controller shield that gets power from a 12V power supply.
Constructing the chassis
Due to the lack of precisely 3D-printed parts, tuenhidiy had to be extremely careful whilst drilling the holes for the threaded rods and round bars. The Y axis had a stepper motor on one end and a place for the Z axis on the other end. The middle portion looks like a 'plus' sign and it slides along the X axis while letting the entire Y axis slide through it. This center piece also houses the Arduino Uno and Grbl controller shield on the top. Finally, the Z axis was attached to the end and a pen was connected to the moving toolhead.
Drawing pictures
Going from a picture on a computer screen to a series of movements for the P-CNC Plotter takes a few steps to get working. The Arduino Uno was loaded with the common Grbl CNC firmware that gets G-code commands from the USB port and translates them into motor positions and speeds. As for the images themselves, tuenhidiy drew them in Inkscape and exported them as a G-code toolpath file. The plotter uses a surface depth of 0mm and a depth value of -1mm which controls how far down the pen goes when drawing.
You can see how well the P-CNC Plotting system works in this video, and you can also view the project's write-up here.