Starting with your form intersections, overall these are really solidly done. Your intersections demonstrate a solid grasp of the relationships between the forms and how they all sit in space. I have just one minor point that I noticed - your cylinders didn't seem to have any noticeable foreshortening applied in most cases. Given that we're working in 3D space with at least a little bit of depth to the scene, we should see the impact of foreshortening at least a little bit on both the scale and the degree of the ellipses at either end of a cylinder.

Moving on, with the object constructions you're off to more than a good start, although there are some points I can remark upon to help you stay on the right track.

The first thing I want to talk about is actually probably the least important, but it is something that stood out the most - your use of hatching. As discussed back in Lesson 2, we don't actually get into shading/rendering in this course and don't use it within our drawings. In this lesson there's a little leeway, in that very limited use of hatching in a particular way can help us to convey a rounded, curving surface. One must always however be entirely aware of why we're putting down a given mark, and how to best approach that goal.

In these relatively old notes I explain a particularly important point - if at all possible, don't put yourself in a position where you have to draw hatching lines that curve. Reason being, drawing that many different lines is no doubt going to result in some of them being a little off, and that will undermine the roundedness of your form by contradicting the illusion you're trying to create. So when we've got a cylinder, instead of hatching along its curvature, hatch length-wise, giving you nice straight lines.

Secondly, try not to leave your hatching lines floating, or ending at some arbitrary point. Instead try to keep them between two clear edges. Hatching lengthwise along the cylinder example is preferable for this reason as well. In the case of a sphere, honestly I probably wouldn't add hatching at all unless I had a very specific reason for it.

Now, there were a few places where hatching would have been okay (you see me use it in this bluetooth speaker demo after all), but you definitely forgot about how we're not supposed to use it at all. In general hatching is really only used to capture shading/rendering, or as a sort of stand-in for texture (when we don't actually want to draw texture by focusing on the actual cast shadows produced by our textural forms), and should be avoided in most cases in this course.

Moving onto another somewhat superfluous, but notable issue, on your kendama drawing, you appear to have missed what I mentioned in the section of the lesson that gave permission to use ballpoint pen:

Ballpoint pen for your linework (don't switch pens to do any sort of "clean-up" pass - use the same pen through all your lines, including construction/box subdivision/etc)

Here you ended up with really prominent line weight effectively redrawing the entirety of the object in order to separate it from the construction. This is also one of those things we avoid entirely within this course. Construction is not about ever redrawing things - it is about building complexity up through the addition of new simple forms. We can use line weight to help clarify specific overlaps, but that line weight is never applied evenly across an entirely line or an entire drawing. It is focused on particular overlaps that need to be clarified.

Also worth mentioning is the fact that line weight itself should only ever be subtle - the thickness of a line only changes enough for your subconscious to notice, like a whisper rather than a shout. It isn't uncommon however for students to confuse line weight (which clings to the silhouette of a form) with cast shadows, which can get as thick as we want, but must be cast onto a separate surface.

Moving on, for the most part I've dwelled only on these superficial aspects because most of your construction is quite solid. The only area in which I feel your construction falls a little short is when you get into the use of more curves, like your tape dispenser. The issue here is exactly what is described here - your curves aren't well enough supported by the existing structure, and so they feel somewhat vague. Your results would have been stronger had you clearly defined most of those forms as flatter combinations of flat surfaces, and then round them out as a final step. This would have provided a clearer bridge from one step of construction to the last, rather than jumping across as you did here.

All in all your work is actually coming along very well, with the main issues being presentation-focused. I do agree of course that ellipses are difficult - they're the sort of thing that require an immense amount of mileage and practice, which is precisely why I allow (and encourage) students to use ellipse guides for lesson 6 and onwards. Students are still expected to practice their freehand ellipses on their own, but at this point we want to keep our focus on the concepts being introduced here, rather than having them get distracted in trying to pin down their basic mechanics. This will continue to be a strong recommendation - getting an ellipse guide that is - for the 25 wheel challenge.

As explained here, as most ellipse guide sets are expensive, I recommend students pick up a master template. It's more limited in the sizes it has available, but they're generally workable enough for our purposes.

Anyway, I'll go ahead and mark this lesson as complete. Just be sure to review the principles from Lesson 2's texture section to ensure that you don't step outside of the bounds of the course in the future.