z issues

Hey all. Just started doing some smaller items and noticed this issue in the pic. The layers are reasonable good and part is solid as a rock however the layers seem to be off in diameter slightly from one another and as best I can tell they are not in an oscillating pattern. I’m using a taz 6 and have unconstrained the top of the lead screws by removing the bearings. Printed a 3d beachy to confirm success and the z banding I had been getting all but disappeared now however on smaller diameter items this is happening…bit stumped lol