I wanted to print a universal battery connector to ease reusing old battery in home made electronic projects.
The holder needs to be circular for the magnet to stick into it.
Yet, mine were square-ish. I then tried several precision and nozzle speed, but still square-ish.
I tried printing several circles to see how bad it could print circles.
Then, I read that the belt might be loose, so I took a look at them.
See how when the nozzle is moved in the X axis? The slack part make it loose 1mm before it actually move. This could explain the square shape.
Because the labists x1 mini does not provide adjustment screws, I had to disassemble it, stretch the belt and assemble it again.
The shape does not look perfectly circle to me, but at least it was enough circle for the magnet to fit into it.