Alrighty, so I can definitely see that you didn't end up using an ellipse guide for this one, and ended up freehanding your ellipses. In general I'd definitely recommend using one (a whole set is expensive but you can get a 'master' template for under fifteen bucks - while the size of the ellipses are more limited it's still well worth it). This is because it helps remove some of the things we work on in other exercises and other lessons, instead allowing us to focus on the challenges and concepts addressed here specifically.

Now, a number of issues have definitely come to light in your freehanded ellipses for these wheels - specifically the fact that they do not maintain an even, elliptical shape. It's notable that you did draw them larger (it can definitely be quite challenging to draw larger ellipses), and from the looks of it, you did not draw these from your shoulder. The tendency to have them turn more into diamonds rather than ellipses suggests that you may be drawing them from your wrist or your elbow. Whichever it is, the pivot you're using ends up not being enough to follow the whole path in a consistent manner, and so there are key breaks in your flow that create the four corners of these somewhat diamond-like shapes.

In addition to this, you've also drawn visibly slowly - which also contributes to the overall stiffness of the ellipses. This is the case in your underlying construction to a lesser degree, but it is primarily present in how you trace over that under-drawing in an attempt to create a more detailed clean-up pass. This kind of dichotomy is something I've strongly discouraged in previous lessons - the idea that our drawings should not be split into a rough sketch and a final drawing. Every single mark we put down is part of the construction, and we never replace our lines. At most, our use of line weight is use to clarify certain overlaps of forms.

That said, if we ignore the ellipses themselves, and the under-drawings, these are actually very well constructed. You've built them up nicely, and the 'clean-up pass' itself is really a full construction in and of itself. The only problem there is that looking at this page for instance, there are marks there that the viewer is expected to ignore, as the drawing ended up taking a different route. Always remember that every single mark we put down on the page establishes forms that exist within 3D space, and these forms cannot simply be ignored or discounted - once placed, they must be respected and dealt with.

After that page, I think you definitely improve in that regard, and end up building out your wheels as singular constructions. I can also see more and more of a shift from outlining and enclosing your textural forms (like the tire treads on the right side of this page) to relying more on implying those forms' presence by drawing the shadows they cast on their surroundings. The difference is demonstrated here, and expanded upon in these notes/video from the newly rewritten texture section of lesson 2.

All in all you're definitely making significant progress and moving in the right direction but the underlying issues regarding your ellipses are hard to ignore. When drawing your ellipses, draw from your shoulder to keep them evenly shaped, and draw them with confidence, avoid any hesitation that will result in a stiff and wobbly mark. And of course, I strongly encourage you to pick up an ellipse guide before tackling lesson 7. If you're struggling with ellipses, then your focus will be entirely split when all your cognitive capacity really needs to be thrown at the difficult topics covered there. Of course, make sure you continue working on those ellipses as well, but do so in the exercises that are specifically designed to develop those skills (as part of your warmups).

I am going to mark this challenge as complete, as you've done a good job in tackling the specific issues covered in this lesson.