Bed Leveling Knob M3 Insert Nut 0.5 pitch

Changed Design for Insert Nuts for better use.

Used Nuts like this one:
https://de.aliexpress.com/item/Rivet-Nut-M3-M4-M5-M6-M8-Flat-Head-Stainless-steel-insert-rivet-nut/32815782417.html