These files are for a cylinder with diameter of 12mm and height of 20mm.

This was designed with SolidPython and can be easily changed to create holders for cylinders of any size.

The cylinder diameter and height, screw hole diameter, and wall thickness are set at the top of cylinder_holder.py

After modifying generate the openscad with:

python3 cylinder_holder.py

then create the stl with:

openscad -o  cylinder_holder.stl  cylinder_holder.scad