one of the things my instructor did at my community college was ask us to draw a centerline to an ellipse. (the center mark lets you do a circle or an arc) After doing some reading, I determined that basic AutoCAD 2016 does not support it. Maybe try some problem solving technique to fix?
More detail: I tell students to draw two permedicular diameters (using the proper layer with the proper linetype, bases on the relative size of the circle), scale them from the center by 1.3, and adjust LTSCALE to change adjust all centerlines in all circles. This works under the biggest circle is about 6.9 times the size of the smallest circle, using three red layers for Center2, Center, and CenterX2 linetypes. Students thinks that's too old fashioned, though. I've never found an automatic way to have the cross, gaps, and extensions proportional to the circle
