Starting with your cylinders around arbitrary minor axes, there are a number of things you're doing well, along with one area in which you are not. Your ellipses are evenly shaped and confidently executed, and you're doing a great job of checking their individual alignments by marking in their true minor axes, doing so in a fastidious manner, and picking up even fairly small misalignments, so as to improve upon them in later attempts.

Where you're running into an issue, however, is in following one specific instruction that was stated in bold in the assignment section of the instructions. You were asked to draw the cylinders with a wide variety of rates of foreshortening. While missing or ignoring an instruction is a significant issue, it does go somewhat beyond this - you didn't only stick to one rate of foreshortening. Rather, you appear to have purposefully drawn all of your cylinders with side edges that remain roughly parallel on the page, as though you were intentionally placing those vanishing points "at infinity" (as discussed in Lesson 1), to simplify the problem ahead of you.

Unfortunately, in doing so, you ended up breaking the rules of perspective.

Reason being, a vanishing point only goes at infinity in a specific situation. It's not something we can control or assert ourselves, based on our desire to simplify an exercise. The vanishing point only goes to infinity when the set of edges it governs in 3D space runs perpendicular to the viewer's angle of sight, rather than slanting towards or away from them through the depth of the scene. What we can control is the orientation of the form we mean to draw - and given the fact that this challenge, like the 250 box challenge, involves drawing forms that are freely and randomly rotated in space, we can pretty much guarantee that this specific alignment is so unlikely that we can just as well expect that it won't occur. Thus, we should always be working with side edges that converge, even if only very gradually, rather than remaining entirely parallel on the page.

Continuing onto the cylinders in boxes, you are more inclined to have your parallel edges converge on the page, though there are some cases where you slip back towards trying to keep things more parallel than they ought to be. Fortunately, there's enough convergence here for me to set that issue aside. Without worrying about that, you are largely doing this part of the challenge well, and I can definitely see a fair bit of improvement. You were somewhat unsure of what you were doing earlier on, but around the 40 mark, the pieces started to fall into place and I can see clear signs of understanding.

This exercise is really all about helping develop students' understanding of how to construct boxes which feature two opposite faces which are proportionally square, regardless of how the form is oriented in space. We do this not by memorizing every possible configuration, but rather by continuing to develop your subconscious understanding of space through repetition, and through analysis (by way of the line extensions).

Where the box challenge's line extensions helped to develop a stronger sense of how to achieve more consistent convergences in our lines, here we add three more lines for each ellipse: the minor axis, and the two contact point lines. In checking how far off these are from converging towards the box's own vanishing points, we can see how far off we were from having the ellipse represent a circle in 3D space, and in turn how far off we were from having the plane that encloses it from representing a square.

Once those pieces started to fall into place, we see a considerable improvement in your judgment of those proportions, so I can see that you've clearly shown a good bit of growth and improvement over the set.

Unfortunately, before I can mark this lesson as complete, we will need to address the significant issue with the first section, so you'll find some revisions assigned below.