Hi, Hopefully I can offer some helpful critique today.

Lets start with your ellipses constructed around an arbitrary minor axis. First of all, many of your ellipses are constructed with a vanishing point that goes into infinity, with both sides of the ellipse being perfectly parallel on the page. Sometimes the lines even diverge, getting further apart. The purpose for this exercise is to understand how foreshorting works through practice so failing to apply forshortening undermines the work you did. For more info, re-read this: https://drawabox.com/lesson/250cylinders/1/reminders

The other main issue is that you often forget to increase the degree in the ellipse that is further away from the viewer. In many of your ellipses the further ellipse has a degree shift that is much shorter then the closer ellipse. This is a big issue, and breaks the illusion of depth on the page.

https://drawabox.com/lesson/250cylinders/1/degree

You really like to jam in as many ellipses as humanly possible on one page. By placing too many ellipses on a page, you are limiting your brains capacity for spacial reasoning as you have to contend with a limited space for you to draw the next cylinder In. I personally would aim for 3-6 cylinders per page at most. Only when one drawing is done should we assess whether there is enough room for another. If there is, we should certainly add it, and reassess once again. If there isn't, it's perfectly okay to have just one drawing on a given page as long as it is making full use of the space available to it. This is also a huge issue with your ellipses constructed in boxes as well, as those pages are so dense with cylinders it is hard to imagine you not limiting your capacity for spacial reasoning.

The other point about your ellipses with minor axis was that you extended the sides of each cylinder using the perspective checking method. This was not required in the exercise, and I am not sure why you did this. Maybe you thought it would help you improve the accuracy of the cylinders or maybe you misread the instructions. Whatever it was, I don’t think it was a huge issue at the end of the day, but don't continue to do that in the future. Instead, stick to the two minor axis lines for the corrections, like outlined in the instructions of the challenge.

https://drawabox.com/lesson/250cylinders/1/stage1check

Now lets move on to the ellipses constructed in boxes. The boxes themselves are a big improvement compared to the mistakes in the minor axis cylinders, however, there is one big oversight you made and it has to do with the error checking method.

You only extended the lines of the cylinders on one axis, while forgot to also extend the lines of the rest of the box, and the contact points where the ellipses touch the enclosing planes into their vanishing points. Unfortunately, this undermines the purpose of the entire error analysis, and thus the exercise as a whole. 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.

If however you neglect, one, two, or half of the lines that we're extending, then you leave places for those errors to hide and go unnoticed. Thus, the growth and improvement we seek to gain in the assigned work, specifically in honing our estimation of those proportions, is limited at best.

Unfortunately, for whatever reason - and that may be something for you to reflect upon and identify - you did not follow the instructions here as closely and as carefully as you should have. I would guess that given the repetitive nature of the challenge, you may not have gone back to review the instructions, to make sure you were applying everything correctly, and may have gone into auto-pilot as a result of the monotony. Even I've done it while I was doing the challenge.

Because of these concerns I have, I am going to request a revision of 100 cylinders total, 50 constructed on a minor axis and 50 constructed in boxes. Make sure to apply all the criticism I have offered here, making sure your lines converge every time, making sure the further cylinder has a larger degree shift, only drawing 3 cylinders per page, and making sure to apply the error checking method as thoroughly as possible. Once you do these correctly, you should be ready to move on. Also, make sure to thoroughly re-read the challenge instructions at least one time and maybe a couple more during the challenge to make sure you don’t miss anything and go on auto mode again.