CNC pen plotter

As this is an ongoing project there is still some things I want to add/improve:

• Replace the Y axis shafts for shorter ones.
• Place an easy to install/remove base to hold the work paper.
• Redesign the penholder to make it stiffer.
• Add a fan to decrease the motor drivers’ temperatures.
• Replace the wooden movable pieces for acrylic ones (or at least paint them).
• Tidy up the wiring.