Dog Leash Routing Clamp

Whenever we occasionally had to tie our dog to his retractable leash inside the house, one problem we observed was that the leash would reach above the table and knock over the stuff on it (such as the red vase pictured above). I therefore decided to come up with a solution that would route the leash downwards from the staircase railing, so that it would reach below the table.

I designed this piece in OpenSCAD. It consists of a two-piece clamp, attached together using two M3 35mm screws, as w