So back in Lesson 0 (on this page), there's a video covering the tools we use throughout the course, which demonstrates the different kinds of ellipse guides out there. Given that these are new videos, it's entirely possible you didn't catch it, though I noticed you're on the discord, so you may have seen the announcements marking their release. Anyway, as explained there, there's basically two kinds of ellipse guides that can be used - there's the cheaper 'master ellipse templates' which consist of a single sheet and include several different degrees, and then there's the more expensive full ellipse guide sets.

It's entirely possible that you mistakenly picked up part of a larger set (which would likely result in ellipses of different sizes, limited to a single degree) rather than a master ellipse template. I'm guessing that's what you mean by "one angle". I would recommend that you try to find a proper master ellipse template as shown in that video. It's not as big of a deal in the wheel challenge (and I'm going to take the limitations you were working under into account when writing the critique below), but in Lesson 7 it will be quite detrimental if you don't have access to a variety of degrees.

Getting started on the structural aspect of your wheels, you've generally done a good job of covering that rounded profile, where the wheel gets a little larger through the midsection, and then smaller out to the sides. This helps a great deal in giving the tire itself an "inflated" appearance, effectively making it feel like if it were dropped, it would land with a bounce rather than a heavy, immobile thunk.

One area in which the structural aspects do suffer is in how you're handling your rims/spokes - specifically how you're leveraging your filled areas of solid black. If we look at wheel 24, we can see that you've filled in those holes with black, but we aren't left with any information on how thick the actual metal of the rims are - the absence of a defined side plane thus makes the structure feel more flat. The wheel as a whole still feels 3D, but the specific component itself ends up flatter. We also run into a similar, but somewhat different issue looking at wheel 14, where you do have side planes for your spokes, but you've filled them in with black. This is similar to form shading, where you're making a surface lighter or darker based on its orientation in space - remember that as discussed here in Lesson 2, form shading should not be included in our drawings for this course. Instead, you'd be drawing the outlines for the entire 3D structure, defining the edge between the side plane and the front/outward face, and reserving filled areas of solid black only for cast shadows, as stressed throughout Lesson 2's texture section.

That brings us to the second part of the challenge - the texture aspect of it, in how we handle our tire treads. This challenge is by design something of a grap - it's very common for students to have completely forgotten about the textural concepts from Lesson 2, given how far removed we are from it, and as a result they're more likely to try to just convey those details however they see fit, rather than adhering to the concepts from the course. So, this challenge serves as a firm reminder to review those concepts before finishing up the course as a whole.

You have certainly fallen into the trap as well, as have many others before you. The most common approach you employ is the same as what I mentioned in regards to your spokes - filling in the side planes with black, instead of designing new shadow shapes that those forms would be casting upon their surrounding surfaces. This - the fact that the shadows define a relationship between the form casting it, and the surface receiving it, entirely through the shape design of the shadow, is what makes it so powerful. Just like everything else throughout this course, it focuses on developing the student's understanding of how these forms relate to one another in three dimensions.

There are other cases however where you rely more on just drawing lines - usually in cases where the tread texture consists primarily of shallower grooves. It gets trickier here because we'll often mistakenly think about the grooves themselves as being the textural forms in question - but that is not the case. Grooves, like any other holes (like in a sponge texture) are not forms - they're negative space, empty space, and the forms in question are actually the walls surrounding them. This diagram helps to explain the distinction.

The reason all this matters is fairly straight forward - while these wheels floating in space may look fine in isolation, when they become part of a larger construction or illustration, all of that closely packed linework, with the high contrast between light and dark, becomes a focal point, drawing the viewer's eye to them whether you want it to or not. Conversely, controlling your cast shadow shapes as these implicit markmaking concepts allow us to (as shown here with these viper scales, where we can make the shadows shallower or deeper depending on what we need, without changing the nature of the forms being depicted), allow us to control where the viewer's eye is attracted more thoroughly.

Now, I am going to mark this challenge as complete - being a trap by design, I do not hold the fact that students forget those earlier concepts against them, though I do expect that you'll be reviewing that material quite thoroughly. I did however want to quickly note before I finish that there are a number of points of sloppiness here that there's really no reason for, given the core principles of this course (planning/preparing before each mark, and so on), and just how far into the course we are. So for example:

• Do not scribble like this

• When drawing the kind of filled black shapes we use for cast shadows, be sure to define them first by outlining them (this is where we actually think about the relationship between the form casting the shadow and the surface receiving it, which is entirely based on the shape of the shadow), then filling them in. Do not paint the shadows on stroke by stroke, as you did here, which results in messy and unclear edges to the shape.