In many high school art classes there is missing the ability to participate for some students who are not able to hold drawing implements/paint brushes. This client has tried adapting things like a milk frother to "hold" a paint brush or pencil with limited success. They would be looking for a system like a vertical plotter which could be switch adapted and could use either a pen/pencil or a paint brush. There are many examples of plotters which exist however most don't have user controlled movement, here are some examples:
https://www.instructables.com/VERTICAL-X-Y-PLOTTER-DRAWING-ROBOT-ARDUINO-PLOTTER/
https://www.instructables.com/SIMPLEST-Arduino-Vertical-Plotter/
Switch adapted means it can be activated with different types of switches and joysticks depending on who wants to use it and what their capabilities are (https://www.especialneeds.com/shop/assistive-technology/switches.html).

Your task is to design a system to enable participation in art class by as many students as possible. It must have different activation methods for different people. It must be easy and intuitive to install and operate. It must also be easy to clean. In addition it should be easy to transport and store.