Here are a couple of links from the net and the forum
5 Ways How to Fix Z Banding/Ribbing - Ender 3 & More - 3D Printerly
[Z Banding / Z Wobble: How to Prevent It | All3DP](https://all3dp.com/2/3d-printer-z-banding/
Here are a couple of links from the net and the forum
5 Ways How to Fix Z Banding/Ribbing - Ender 3 & More - 3D Printerly
[Z Banding / Z Wobble: How to Prevent It | All3DP](https://all3dp.com/2/3d-printer-z-banding/