Handle on my mop snaped so here is my design to fix it.
It's hollow inside to save some cost, feels strong, if something will change I'll make an update.

Instructions:

1. print it horisontaly to avoid handle snap on layer lines while used
2. I have printed it with 30% infill PLA

Also I have attached FreeCAD file with table in it, so you can play around with different sizes.

CAD file has two parts, actual whole tube and ring to test fit, here they are

Final form was made in blender so you can play around with everything around base tube form you get from CAD.

Feel free to contact me if you find issues in the design or need some help with adapting it to your measurments