Prusa i3 MK2 as a plotter

thingiverse

I wanted to label a CD and had only my Prusa i3 MK2 3D printer on hand. Since I didn't wanted to create a permanent installation I designed this part to simply slip over the extruder stepper motor. As it turned out I did not need a screw at all to clamp the holder to the stepper motor - it works fine only by friction. The pen is held in place by some holders which I hot glued on. It uses two rubber bands to hold the pen. This works better than I expected since the rubber band gives enough flex (in z direction) so that the pen can move slightly up and down so that it is not pressed hard against the plotting surface and therefore damages nothing. This was the first 3D part I designed and printed. Therefore it is not ultra high quality and contains some flaws like the unnecessary screw terminal. If a screw presses the semi-halfs together the whole part warps and is then crooked. See it in action: https://www.youtube.com/watch?v=YQdHdr4Irz8 Workflow to plot something: To plot something I created an SVG file with the image to plot (in the case of the video the outline of the DVD with the text) and then used http://www.makercam.com/ to generate the G-code. I then open the G-code file and add the G28 X Y command (G28: Move to Origin (Home), see http://reprap.org/wiki/G-code) remove any T and M commands (e.g. T0 M6 and M3) in the file See the following example file (unmodified): (Generated by PartKam Version 0.05) G21 G90 G40 (profile 1) G0 Z15 T0 M6 G17 M3 G0 X40 Y22 G1 Z-1.5 F800 G3 X42 Y24 I-11 J11 F1500 And now modified: (Generated by PartKam Version 0.05) G28 X Y G21 G90 G40 (profile 1) G0 Z15 G17 G0 X40 Y22 G1 Z-1.5 F800 G3 X42 Y24 I-11 J11 F1500 You really need to experiment a moment to get everything right and also consider the z movement to "activate" the pen. I do this directly in Makercam and usually use a save height of 5 mm and no plunge depth at all. Another tip: if you use the Makercam G-Code straight on the 3D printer I got many errors and figured out that the numbers (a line usually looks like "G3 X44.24111675126903 Y39.01015228426396 I-13.98984771573604 J-2.6675126903553297") are too long. So I wrote a little cleanup PHP script (cleanup-script.php) which rounds the numbers to less decimals (the line looks afterwards: "G3 X87.8122 Y95.9645 I46.0305 J46.0305"). This works fine. I use the latest Prusa i3 MK 2 firmware on my printer, the 3.0.9 version. And I use Pronterface to stream the G-code to the printer (connected via USB). Print Settings Printer: Prusa i3 MK2 Rafts: No Supports: No Resolution: 0.2mm Infill: 20% Notes: The part is designed for Prusa i3 MK2 (cable holes at right location etc.) and might not work for other printers.