A pen mount for Artillery Genius/Sidewinder X1/X2.
This 3D model is a remix of https://www.thingiverse.com/thing:5852434, based on https://www.thingiverse.com/thing:4794583.

I've upgraded it by replacing the need for a hex nut and metal screw with a 3D printable thumb screw and threaded hole. Now, it's fully printable and you can easily swap or move the pen without tools.
For best results, print with a 0.15mm layer height.