We decided we wanted to make a system that could be controlled via a tactile input such as a joystick or rollerball control that would translate to movement of the robot thereby creating art.
Initially we were thinking of creating an etch a sketch like system with motion in the x and y direction but decided that this may be difficult to conform to the scope of this class.
We finally decided on a drawing arm that would be on a rotating base. The arm would move would be formed by a set of links that would move forward and backward covering the positive and negative y directions while the rotating base would cover the positive and negative x directions. Realistically speaking, the system would translate to controlling of r and theta values in a polar coordinate system rather than an x-y coordinate system.