I've spent the last 5 years ignoring the missing tips on my spring door stoppers from cats and children pulling them off and losing them. After searching every hardware store and as much of the internet as I dared, I gave up because someone decided you have to buy a whole new door stopper in order to replace the tip.

So I made my own.

Print in TPU. Each tip is approximately 1g of material.

The inner diameter is 9.3mm and provides a pretty tight fit on the door stopper which is about 9.4mm.

It has an air pocket at the end to allow some compression when a door hits it. I did 25% adaptive cubic fill to support this space while leaving it fairly open.