Kita-Boshi mechanical pencil barrel generator

You may use the OpenSCAD script shared on GitHub to generate a model with your own customization and printer settings. I would recommend to use your minimal printer tolerance setting and then file down the inside of the 3D printed barrel until you get the perfect fit to easly slide the shaft. Also the narrowness is the key to creating the thread at the first assembly.

There is no need to have programming knowledge to run this script, however, you will need to have the OpenSCAD 3D model compiler installed on your machine. 

The model on the photographies was printed in PETG on my Prusa MINI+ and then it was sanded down in order to obtain an pleasant and smooth surface. The pencil sharpener displayed in the pictures is also available to download.