The blades on my Polycut mowing head kept snapping when hitting small rocks or twigs and I figured I could print some out of TPU.

I've tried hitting large rocks on purpose, the only visible damage to the blades was a seperation between the walls and infill but it was still cutting fine, I recommend printing with 100% walls on the tips to avoid this issue.

Supports may or may not be required depending on your printer's ability to print TPU overhangs.