12:39 pm September 5, 2019 By Julian Horsey

A unique pen plotter has been created which utilises a robotic arm to be able to draw illustrations in a variety of different colours and styles. Aptly named the Mechpen, pronounced “McPen”, project takes the form of a SCARA (Selective Compliance Assembly Robot Arm) design, with two parallel axes controlling the x-y movement of the arm. Educational Robot Arm

Custom written software converts SVG graphic files to gcode suitable for printing. Enabling the pen plotter to use a selection of different stroke and fill types, and separation of different colours into individual gcode files to be plotted with different pens. check out the demonstration video below to learn more about the Mechpen SCARA Drawbot.

Watch this video on YouTube.

“The brains behind the arm are two-tiered. An Einsy RAMBo board, designed for 3D printers, controls the stepper motors. Above that, a Raspberry Pi runs Octoprint to control the ‘bot. This choice turned out to be very convenient for working around a mechanical issue: the elbow flexes too far in the Z-axis. The difference in pen height between the elbow at 90 vs 180 degrees was 20-25 mm; too much to fix with just a spring-loaded pen. The solution: use a bed-leveling algorithm designed for 3D printers. A VL6180X distance sensor measures the distance to the paper over a number of grid points, then the software moves the servo up and down accordingly while drawing to keep the pen on the paper.”

2.5kg Robot Arm
Latest Geeky Gadgets Deals Disclosure: Some of our articles include affiliate links. If you buy something through one of these links, Geeky Gadgets may earn an affiliate commission. Learn more.