Yet Another Wiring Pen

Using normal thread bobbin that is selling for sawing machine as 11.5mm diameter.
It is designed for 0.2 thru 0.7mm UEW wire.
Cap(Nozzle) and Body were separated and screw coupling.
Your 3D printer condition for allowance of screw coupling may require adjusting nozzle size.
My case M6 screw design applied but 5% increase nozzle side(Male) are necessary.

PLA is recommend.

Printing method.
Please consider placement on slicer. (Please take look pictures of slicer placement)

WiringP3a.stl : bobbin holder pin.
WiringP1.stl : Body ** It may require support for male screw
WiringP2.stl ; Nozzle original size ( It may need adjust for your printer
WiringP4.stl : Nozzle 5% enlarge female screw diameter.

If you need adjusting coupling screw
Then use slicer scaling feature but only applied screw diameter 2 direction only.

Photo shows actual print WiringP2.stl enlarge entire +5% for diameter direction.
WiringP4.stl is designed after print for next printing as internal fem