Remember the AxiDraw? It is a wonderful robot that can draw and write like a human. If you are looking for a cheaper option, you should give the EleksMaker EleksDraw XY Plotter a look. It comes with acrylic plates and aluminum rods. The robot is compatible with EleksCAM and InkSpace.
This 2-axis drawing robot has a stepper motor with accuracy up to 0.01mm. It has a working area of 28x20cm and continuous working time of 10 hours.