First print the STL files located in the Hardware folder. For the pen arm and holder you need to choose the right parts for your printer!

For an Ender 3 you have to print a pen holder and a arm for your specific Ender 3 Version (1 or 2). Both are located in the Hardware folder.

For a non Ender 3 printer you need to print a BLTouch mount as the pen holder arm and a pen holder from the Hardware folder. You can use a original BLTouch mount or print one yourself from Thingiverse. Just search for your printer and "BLTouch" and you are likely to find a fitting one. You also need to print a fitting pen holder from the BLTTouchPenHolder folder. The holders come in different distances and heights. You need to selects the correct distance so that there is nothing to the right or left of the holder and tip of the holder is approximately 4mm above the print surface. There is probably some trial and error involved when figuring out the right versions of holder.

clearance needed along the X axis

clearance needed along the Z axis

It´s advised to print all the files with a brim so they are perfectly flat and don´t topple over while printing.For working with 6 colors you need to print 6 pen caps, the pen rack, the pen holder arm and one of the pen holders.

For the pen holder part you can choose between a variant for Sharpies only and one for Sharpies, Amazon Basics Markers and Shuttle Art Markers. The later one is a little bit lose for Sharpies so it´s advised to use the first one if you only want to use Sharpie markers.

recommended printing orientations

To prepare the sharpies for printing, place the end cap on the back of the pen. The cap should hold the pen tightly and don´t slip of easily.

pen with end cap

You need to mount the pen holder to your extruder head first. To do so you need to unscrew the 2 screws shown in the picture.

location of the screws

Now put the mounting part in place and screw everything back in. After that you can mount the pen holder to the mounting arm with 3 M2 screws.

mounted pen arm

mounted pen holder

Make sure the pen can slide in and out of the holder easily. If not you may need to sand down the piece a bit.

pen in pen holder

pen in pen holder

In case you don´t have an Ender 3 you need to mount the pen arm using a BLTouch mount. After mounting the BLTouch mount you can screw on the arm from the top as shown in the picture.

pen holder screwed to BLTouch mount

The pen rack needs to be mounted to the upper t-slot profile of your printer.

pen rack mounted with screws

If you have an Ender 3 you should have 2 spare screws and corresponding t nuts you can use for that. Just use them screw the rack on the profile.

If you have a non Ender 3 printer you can mount the rack using some zip ties.

pen rack mounted with zip ties

Important: when mounting the racket you need make sure that a pen sitting in the pen holder can be easily sliced in and out of the individual rack holders! If it doesn't fit perfectly just slightly unscrew the rack and reposition it until it fits.

first pen position

last pen position

To reduce stress on the bowden cable it is advised to place the rack as far left as possible.

When changing the pens the printhead needs to do a lot of Z-travel. Far more than it would normally do. To greatly speed up the printing/painting process it´s therefore advised to increase your printers Z-axis speed. For an Ender 3 this is done under Control->Motion->Velocity->Vmax Z. I did dozens of prints with the speed set to 25. Higher speeds may very well also be possible but do this at your own risk.

Vmax Z set to 25

Please Help: Right now the parts are designed for an Ender 3 printer but adapting it to other printers should be fairly easy. If you design a different pen arm or rack for your printer please share your design by opening a pull request, contact my via [email protected] or do a remix on the Thingiverse page.