Kossel column enforcement

I've created those column reinforcement squads for reduce vibration on top.

For 15x15 openbeam

BOM: 9x M3 Screw 0.8mm length
9x M3 Nut
9x Grover washer (1mm max)

The nut on the column is reworked like a T-nut (thin side, but it works) for column open beam).

MOUNTING: Insert the Internal screw (with grover washer) in the hole +nut other side;
Place the external nut in right position in the open beam;
Turn the squad pe