What is it?
This thing lets you mount a pen, marker, or drag knife to the Monoprice Select mini to plot, draw, engrave, or cut things. It adds another level of things you can make and do to your 3D printer.

Tell me about it?
I saw Arpruss's cool springy pen holder on Thingiverse, and wanted one. I originally remixed it to add the little mounting ears for the MPSM fan holder. Unfortunately that wasn't rigid enough. The Pen flopped around horribly. I redesigned it to fit snugly around the heat sink to prevent this. With this modification the pen is very rigid in all of the non-springy directions.

How do I print it?
It requires support to print, unfortunately. I printed mine on the MPSM, and have attached my .gcode file if you want to use it. It's set for a bed temperature of 60C and a filament temperature of 200 and 205. This seems to work well with the White Monoprice brand PLA. You also need two #6 self tapping screws or a similar metric screw to hold the pen in place.

How do I use it?
Unclip the fan from your extruder and use a paper clip, twist tie, or binder clip to hold it up and out of the way. Gingerly push the pen holder onto the heat sink. It's designed as a snug fit, and you may have to scrape it a bit to make it fit on just right. Then hold it in place with the fan mounting spring clips. Mount the pen in place at the right height, send it your g-code, and draw away.

Making the gcode.
I used inkscape to make the gcode for the drawing. Here's how.

• Open Inkscape
• Change the "page size" to the size of the MPSM bed.
  • File >> Document Properties
    Page Size >> Custom Size
  • Height: 100 mm
  • Width: 100 mm
• Draw some text
  • On the left side menu, click the letter A
  • Change the font options using the menu at the top
  • Click the "paper" and type something
• Convert the text to a "Path"
  • Click the arrow tool at the top left of the left toolbar.
  • Click the text you typed.
  • Click Path >> Object to Path
• Make the G-Code
  • Click Extensions >> GcodeTools >> Path to Gcode
  • On the Preferences tab, change the "Directory" option to a folder where you can save files.
    • For me, this is c:\users\egreene\Desktop
  • On the Path to Gcode tab, click Apply.
  • The gcode should be saved to your target folder.

Setting the pen at the right height
I just made this thing and don't have a good workflow for it yet. I knew I didn't want to move my bed height and I didn't want to drag the print head across the paper. Here's how I do it.

• With the pen out home the printer using the front panel menu.
• Move the print head where the pen will be above the bed using this Gcode

(Run this code with the printer homed and the pen OUT)
G21 (Switch to metric)
G90 (Absolute Positioning mode)
G0 X10 Y10 Z5 (Move above the print bed)

• Now drop in the pen and tighten down the screws gently.
• Reset the zero position on the printer with this Gcode.

(Drop in the pen and tighten the screws)
G92 X10 Y10 Z0 (reset the zero position)
(Ready to print)

Sending the gcode.
I used Pronterface to send the Gcode commands above and to send the inkscape code

• Launch Pronterface
• Connect to the printer
• Send the code above to get the printer ready
• File >> Open >> Pick the output_000x.ngc file saved from Inkscape.
• Click "Print".

My First test Plot
https://youtu.be/bNElitMUsGo

Possible improvements

• The Pen holder is too small to hold a Sharpie.
• Some software for positioning the pen and setting zero would help a lot.
• Add some clips to hold the fan so it doesn't have to be clipped out of the way.