Unfortunately the overall purpose for the promptathon is to give students something else to do, so they don't actually work on their homework. We also provide a 10 day extension on any expiring credits, ultimately attempting to achieve a sort of "stasis" where the week's pause has no actual impact on a student's ability to complete the course. This is all in the interest of providing our staff with a well deserved break, as explained in the announcement. While we'd love to be able to just shut off submissions altogether during that time, it wouldn't actually solve the problem, as it would simply result in a massive inundation of work at the end of the event, eliminating any benefit from the vacation.

So, for that reason, simply allowing students to put a submission on hold in some fashion would not work. We actually need students to take a break as well. And while we appreciate the whole "don't rush with this submission", that similarly doesn't really work. We get submissions every day, and so we need to take care of them lest we end up with a considerable backlog.

Anyway, moving onto your critique, given that you were unable to find an ellipse guide (most students end up purchasing a cheaper master ellipse template online, though not all students are able to get them), I'm going to try to leave out any of the comments regarding the expected kind of issues that would come from freehanding them, as they aren't really pertinent to the critique.

Looking at the structural aspect of your wheels, you've handled these quite well. You're including a clear bump through the midsection of the wheel's profile, which helps it to appear solid yet inflated - giving the impression that it'll land with a gentle bounce, rather than a heavy thunk as though it were made of steel all the way through. You're also doing a good job of minding both the front face of your rims' spokes, as well as their side faces, which goes a long way to help make them appear three dimensional. You've handled their arrangement quite nicely as well, which can be quite tricky, since we're attempting to lay out elements along a circle in 3D space, all spaced out evenly.

Moving onto the textural aspect - that is, the tire treads, which being made up of forms set out along the surface of a larger cylindrical structure, are indeed something we'd tackle using the textural principles of Lesson 2 - this challenge is something of a trap. Given how far removed we are from Lesson 2, it's very common for students to forget what implicit markmaking is, and to attack this problem through a variety of ways. Here, you've definitely done the same, largely relying on explicit marks.

For example, in wheel 18, you ended up constructing the larger chunks entirely. In wheels 19, 21, 22, etc. you've similarly constructed each and every textural form, though you have attempted to employ some larger filled areas of solid black as well. While that suggests you're moving in the right direction, what you've done here is fill your side faces in with black, rather than actually creating new cast shadow shapes, which themselves define the relationship between the form casting the shadow, and the surface receiving it. As a rule of thumb, if you're filling in a shape that is already existing in your drawing, you're probably not casting a shadow. Shadows require a completely new shape to be designed, and it is that shape which defines that valuable spatial relationship.

Here's a diagram of the difference between them that I did for another student, which I have taken to sharing with others. Below I've pasted the explanation that goes along with it:

In the top, we've got the structural outlines for the given form - of course, since we want to work implicitly, we cannot use outlines. In the second row, we've got two options for conveying that textural form through the use of filled black shapes. On the left, they fill in the side planes, placing those shapes on the surface of the form itself, and actually filling in areas that are already enclosed and defined on the form and leaving its "top" face empty. This would be incorrect, more similar to form shading and not a cast shadow. On the right, we have an actual cast shadow - they look similar, but the key point to pay attention to is shown in the third row - it is the actual silhouette of the form itself which is implied. We've removed all of the internal edges of the form, and so while it looks kind of like the top face, but if you look more closely, it has certain subtle elements that are much more nuanced - instead of just using purely horizontal and vertical edges, we have some diagonals that come from the edges of the textural form that exist in the "depth" dimension of space (so if your horizontals were X and your verticals were Y, those diagonals come from that which exists in the Z dimension).

Now, your wheels do look great, but the thing to keep in mind is that while they're fine floating alone in the void like this, packing so much linework into a tight space can cause problems when these wheels are used as part of a larger construction, like a car. Reason being, all of that contrast creates a focal point, it draws the eye to it whether you want it to or not. Conversely, working implicitly, with only the cast shadows to imply the presence of the forms casting them (rather than constructing them), we can alter just how dense our marks are, without altering the nature of the texture being conveyed. Like a sun dial, which will cast a small shadow at high noon, and a very long shadow at dawn or dusk, we can make our textural forms cast longer shadows or smaller shadows, or blast them out entirely, as shown here.

So, be sure to keep this in mind going forward. Of course, being that this was an intentional trap to serve as a bit of a rude reminder, I will not be holding you back over this. I'll go ahead and mark this challenge as complete.