Circle Leveling and Adhesion Test.

Circle Leveling Test
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This a quick 1 minute bed leveling test. Mainly for a **glass mirror bed** to also test adhesion.

I was having some difficulties with a large print, due to poor leveling and nozzle height. Straight lines were drawn fine, but circles, especially small ones were dragged around which were due to the nozzle height being too high. Thus, this test was born. It's a bit more stringent than a square test.

####How to use this for leveling:
Much easier to observe on a mirror or light colored bed.
Observe the four corners and the center. They should have uniform coloring. If a corner is more transparent, it's too close to the nozzle. If a corner is too solid colored/not circular/not sticking properly, it's too far away. Adjust your leveling screws until everything is uniform.

If the center and the corners differ quite a bit, your bed is warped. Get a new bed/mirror.

For example, my four corners became more and more translucent as it got closer to the edge.