My mum needed to hang some curtains up, and I decided it was a good chance to make something more than just cookie cutters with my printer!

The scad file is pretty rough, so be careful to check the outcome if you change any values.

The curtain rod in this case was 15 mm diameter, and the screws about 5mm diameter.
My first iteration had a smaller hole, with the plan being to have the screw dig in, but it just split the print.
So now the hole is bigger than the screw, which worked well.