“This instructable explains how to make a CNC plotter using an Arduino Uno R3, an SG90 servo, two NEMA 17 stepper motors, a few pulleys, and a short length of aluminium extrusion.
Construction is simple … all you need are a few drills, a sharp knife, and a hacksaw.
The plotter has an on-board interpreter that recognises the g-code output from Inkscape. All that is required is an XON XOFF terminal that can send text-files one line at a time.
The plotter may also be controlled using a cell-phone or tablet as explained in my instructable https://www.instructables.com/id/CNC-Graphics-Tab…
Specific XY coordinates for this plotter are reached by varying the angle and length of a linear actuator. Print sizes greater than A4 are possible by increasing the length of the actuator arm.
The plotter produces excellent watercolour outlines but is not a precision instrument as the resolution varies across the print area. Best-case resolution is 80 steps/mm … worst-case resolution is 5 steps/mm when the actuator arm is extended to 400mm.
The estimated cost to build this plotter, excluding the power supply, is less than $80 USD
Images
The opening photo shows a closeup of the actuator mechanism.
The video demonstrates the plotter in action.
Sample plots are shown in photo 2.
Eye Hazard
Keep clear of the plotter when it is working, especially the rear, as the actuator can suddenly extend to its full length.”