Sewing machine thread cutter

You will need a segment of 17.5 mm 60º blade which will be inserted while printing. 

With standard 0.2 mm PLA resolution you might need to pause at layer height 11. Don't remove the hot plate when the print is paused, or the model might detach. 

When adding the blade segment you can add a dab of superglue. Continue printing after placing the blade in place. 

uses 60º blades 17.5 mm wide