This DIY pen plotter has delta kinematics and a tool changer

Arduino Team — July 31st, 2026

Pen plotters are kind of neat, if you like the idea of marking paper without resorting to printing. But almost every pen plotter out there is basically the same: Cartesian movement in two axes, with some sort of actuation in Z to lift the pen. This DIY pen plotter built by András Vujovits is different and includes some very unique features.

Unlike most other pen plotters, this one has delta kinematics. In two dimensions like this, that means it has two parallel arm linkages, each with an endpoint on a carriage riding on a rail. By moving the two carriages relative to each other and the bed, it can position the end effector anywhere within its work envelope — it just takes some fancy math.

On top of that, it has a tool changer. That lets it swap between pens, markers, and potentially other kinds of tools (maybe a drag knife?). And on top of that, it has a paper feed mechanism that pulls fresh paper across the bed, like a miniature treadmill. 

Most of the pen plotter’s parts were 3D-printed. The linear rails, belts, and various fasteners are all off-the-shelf parts.

For control, Vujovits chose to pair an Arduino® Nano™ with a GRBL shield equipped with stepper drivers. Standard software won’t produce G-code appropriate for this machine, because the delta kinematics are completely foreign. For that reason, Vujovits developed his own software that takes an image file, creates toolpaths, and spits out files. It makes an XML file, which is basically a custom save file. It also generates a G-code file, which contains the motor commands that take the delta kinematics into account. From there, a standard G-code sender will get the file on to the plotter and it is ready to draw.

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