Coupling 5 to 8 mm for trapezoidal lead screw

thingiverse

Coupling 5 to 8 mm for trapezoidal screw. It has good centring and reliability. You need 6 m3 nuts. 3 6mm screws and 3 8mm DIN913(or similar). You can use any screws if u want generally. In the hole for motor shaft you can see recess. Try to make the seam there. You can do this from Kisslicer for example. I don't know if other slicers can do this. May be you have to drill a hole for motor shaft a little.