Thru hole parametric universal spool holder

Parametric universal spool holder is very good, but i need a thru hole for mounting more than one spool in the same M8 rod, thanks to the provided OpenSCAD sources is easily to di this edit:


Rod diameter 8.5 instead of 8.1

// rod diameter
rod_d = 8.5;

Center rod height doubled in order to make the pass thru

// the center rod
translate([0,0,max_d/2+bearing_h+.1]) cylinder(r=rod_d/2, h=max_d*2, center=true);

https://youtu.be/0xe9wTTh_zo

For easily insert the bearing into th