Final challenge drawing arm starting post

For the last challenge we had create our own challenge that has a building and a programming aspect. For this challenge I decided to build a drawing arm robot that makes four different designs depending on which button I press of the four buttons on the brick. I'm going to start by building the drawing arm, then programming it so that draws different things by trial and error. I got the idea from a YouTube video https://www.youtube.com/watch?v=r8s6GkPP5EM Mine will be different from the one in the video for a couple reasons, one being that I'm building mine from scratch, another is that while in the video the robot is programmed in Java mine will be in the Ev3 code, finally mine will have four pre-set buttons to do designs where the robot in the video takes designs that you make on your computer and uses them.