I needed to center my pole in a circular holder. They had different diameters.
I created a tool for centering. In the files you will find a SCAD in which you can adjust the parameters as needed. The defaults are for a Decathlon 5m fishing pole and a Decathlon fishing rod holder.
Recomended material is PETG.
Rado OM2ZZ
The author marked this model as their own original creation.