This is an attachment for the compact extruder I already published. It is a holder for a pen, pencil or crayon to use your 3d printer as a plotter.
The way is designed is to be permanently mounted on the carriage but can be removed as well with just 4 screws.
The purpose of this was to draw PCB masks directly on copper laminate boards for etching, but you can draw anything you like and use the 3d printer slicer to generate the g-code to plot your drawing.
There is a little bit more to do than normal 3d printing, but once you set up the parameters it is pretty easy.

For pcb etching is easy because pcb softwares allow to export the pcb layout in dxf format, then you can extrude the drawing using a CAD program to the minimum height your slicer accept and add a few g-code parameters to send to the printer before it starts to print.
I extrude it to 0.3mm but if you make it higher the only thing that can happen is that after drawing the first layer, the print head will lift for the second layer and the pen will not touch anymore and just draw into air.
For drawings, there are different ways, like Openscad has a function to extrude .png files, or other CAD software may have the possibility to extrude images or text.
I use Openscad to extrude the DXF files (it's 1 lines of code " linear_extrude(0.3) import("filename.dxf"); " )
For png files, it is simple too, I included an example file, the only thing is to create the image using black against a white background. Openscad will extrude a 100mm high solid with a full base, just use intersection with a 0.3mm thick cube and you will have your file for slicing.

On my slicer, I removed all the parameters that heat up hotend and printbed, and added a Z offset to adjust the zero level as the writing tip is a bit lower than the printer nozzle.
How low depends on the measures you choose for the holder, but should be minimum a couple of mm lower than the nozzle and maximum depends on the position of the pen and if it will hit something when you will home your extruder.

I send a "G1 Z10" just after the beginning "G28" homing, so before moving to the printing position it will raise from the printbed.
To adjust the height of the pen, I use "M206 Z" and the first time you should set is high to be sure to be clear of everything, then adjust it slowly to find the right height and then add this to the prefix parameters of your slicer and from now on it will be done directly when you slice the drawing.

Depending on the tip size of the pen, set the slicer resolution.
0.1 extrusion nozzle will work fine for ball pens, 0.2mm for fine tipped markers and 0.3 for markers like the one I used in test1 video.
Set nozzle lift (mine is 2mm) for translates.
Print speed doesn't really matter, you can draw pretty fast, just slow down for sharp corners as you may bend the drawing tip if you do it too fast.
For the file, I create my pcb with Kicad, export the dxf layout and use openscad to extrude it 0.3mm, then I have a customized folder with a Kisslicer setup for the plotter with the said parameters, slice it, insert the pen in the holder and print...
It may sound a bit complicated but it's not, it's like normal 3d printing and once you have your parameters already in the slicer it's even faster because you don't have to wait for warming up extruder and bed.
The good point of printing the mask directly on the pcb is that in case it is not printed well, you can restart and draw over it, or use some solvent, remove the drawing and print again...or you can print the mask on the photoresist film or use the printer to draw on flat objects or just print on paper...
If you have a good setup and the pen is stable in the holder and it is fine enough, you can print at resolution like your 3d printing stuff. If you use a permanent marker, the resolution will depend on its tip size. You can even use this technical drawing ink pens that draw 0.1mm lines, just be careful to adjust the height properly as too much pressure will end up bending the tip.

Videos:
https://www.youtube.com/watch?v=lpEckPdj5sY
https://www.youtube.com/watch?v=1-n2zXdDo48
https://www.youtube.com/watch?v=cAStCGr0qjw

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I created these eBay links where you can find components, filaments and spare parts at the best prices. These are just links to eBay and Aliexpress items, where I normally buy spare parts and materials for my printer and projects. Clicking on these links will support a little bit these projects.

PCB perforated boards - Resistors eBay - Capacitors eBay - Diodes eBay - led - Wire terminals eBay - Arduino and modules eBay - Raspberry and modules

Prototype PCB board Aliexpress - Resistors Aliexpress - Capacitors Aliexpress - Diodes and LED Aliexpress - Arduino and modules Aliexpress - Raspberry and modules Aliexpress

PLA Filament - eBay - ABS Filament - eBay - TPU Filament - eBay - PET Filament - eBay

Complete extruders - eBay

Heat blocks and heaters - Aliexpress

Standard nozzles - eBay - Standard nozzles Aliexpress

Volcano nozzles - eBay - Volcano nozzles - Aliexpress

GT2 pulleys - eBay - GT2 pulleys - Aliexpress

GT2 belts - eBay - GT2 belts - Aliexpress

Linear bearings LM series - eBay - Linear bearings LM series - Aliexpress

NEMA 17 step motors - eBay - NEMA 17 step motors - Aliexpress

3d pen - eBay

100$-200$ 3D printers - eBay - 100$-200$ 3D printers - Aliexpress

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Filament extruding machine - eBay -
Filament extruding machine - Aliexpress

Pellets for extruding machine