Turn 3d printer into plotter.
This is a simple add-on on top of an existing extruder for Ender 3d printer. The concept can be applied to pretty much any other extruder: create a tight outline that you can pull on the extruder (in our case, on its fan box) and fix it (in our case, with a screw).
Note that this add-on is different from most of the existing ones: it uses a plastic spring. That means the marker is firmly pressed against the surface and in the same time, it will not be pressed too hard. So you do not have to make marker vertical positioning too accurate: few mm error will not affect anything.
I used it to create PCBs, so below you can see results. Of course, it can draw other types of images, but generating g-code files is up to you. As for PCB, I used my PCB Editor
Photos:
And source file:
Conclusion.
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