Sean has built a 2D plotter that is controlled by Arduino, with 3D printed parts, and programmed with a Scratch variant called MBlock.
Anyone interested in learning about programming with MBlock can find information on the Instructibles website: How to use graphical programming software to program Arduino and robots?
Also, some parents asked about where they can get an Arduino board. You can buy Arduino Uno and decent kit from Amazon for £24. It has loads of bits …
Here is a video of Sean’s plotter in action: