Circles not so circular

Good morning everyone. I have an interesting issue that I have run into on 2 of my Taz 6’s now. Anytime I have a model with a circle in it, I get a shape that is more like someone’s eye. The circle is slightly oblong with subtle points at the two ends. On the first machine this was happening on I believe I was able to fix it, at least it seems way better, by tightening the set screws on the drive pulley’s on the bed motor. But on the second machine, that does not seem to be the problem. I tightened the drive pulley for the X and Y axis but no change. Has anyone else run into this problem and have a suggestion?

One note about this print, the one side on the outer edge is supposed to be flat. Use the inner circle as a reference. When you look closely, it almost appears as if the right half the circle just shifted up.

I would suspect one of your axis’s are binding. Perhaps one is too tight?

It sounds like you might have a loose belt. That can cause circles to come out of round. When you look at the model on your build plate, if it goes oblong from right to left, try tightening the x-axis belt. If it’s oblong front to back, try tightening your y-axis belt.