Office Chair Flat Repair

My Office chair likes to slowly deflate. I created this thing so I could print a few and make my chair stay whatever height I like.

I've uploaded two other versions of this thing that should work better. I found the gap in the first version to cause the rings to crush down into each other. I also uploaded v3 with a wider gap as v2 might be too small and fuse together.

This thing was made with Tinkercad. Edit it online https://tinkercad.com/things/gE8pTrNFW4s