Starting with your form intersections, your work here is generally decently done. This is an exercise we come back to a lot through this course, and this is not the last time you'll encounter it. It focuses on the same overall goal as the course as a whole (one's spatial reasoning skills), and so by throwing it at students at the beginning and then periodically towards the end, we can look at how their overall understanding is progressing. At this point we don't expect students to nail it perfectly (we don't expect that throughout this course in general, but certainly not now), but it is normal to see students struggling with the more complex kinds of intersections (especially those involving curving surfaces), but to be more confident with those involving flat surfaces only. That is roughly where you are right now.

To help you keep progressing, there's two main kinds of mistakes I want to call attention to in your work, which I've marked out here. Along the top is a demonstration of how we identify the nature of the intersection line itself between the sphere and cylinder. It's all about following the surfaces of both forms simultaneously, but that's a lot easier said than done. By looking at the different places in which the forms are intersecting, we can identify a few things - firstly, most of the intersection occurs along the length of the cylinder, where the cylinder can actually be considered a flat surface (at least in that one direction). If we think about this like math, a flat surface is 1, in the sense that multiplying a number by 1 does not change the value - and so we can follow the curvature of the sphere.

As that intersection continues on and no longer follows the straight path of the cylinder's length, but rather starts to wrap around it, there the cylinder's curvature comes into play, causing the intersection line to curve back along itself.

This is definitely tricky to wrap one's head around, and it definitely requires putting it into practice to continue getting it to sink in - but in the interest of further helping you with that, here's an additional diagram that helps demonstrate the idea of thinking about our intersections in pieces, focusing on the nature of the surfaces that are interacting with one another. It also shows how the intersection line changes if we replace one hard edge with a rounded transition.

The other kind of issue I marked out on your work is a little further down, dealing with the box-box intersection where I've marked out a red line. Like the intersection you drew, it's composed of two straight lines that meet at a corner - but in yours, that corner is floating arbitrarily. In mine, the corner is placed specifically at the edge where we transition from running along the upper face of one of the boxes, to its side face. It's important to consider why we're adding a corner in the first place.

One thing to keep in mind, in general, is that actions taken randomly that you can't explain the reasoning behind aren't useful for learning. Actions taken based on incorrect understanding however may result in mistakes, but they are extremely useful for learning because they give us something we can counteract by explaining why that may not have been correct.

Continuing onto your object constructions, I think your work here unfortunately does show that you've been away from the course material for a good while, and that you may not have been keeping up with your warmups as much as you should have. This has resulted in at least one major issue that is present throughout your work - the boxes you started your constructions with were frequently skewed, with edges that would diverge as they moved farther away from the viewer rather than converging, or edges that remained largely parallel with one another on the page instead of converging as they should.

So for example, we can see this in your handgun, where the box actually gets larger towards the rear. One thing that can help with this is your ruler. While the ruler's great at helping you draw straight lines, it can also show you the path your line is following if it were to be extended much further, but without actually having to commit to the line first. In other words, by moving your ruler around and seeing how it converges with the other lines of the box, it can help you to avoid cases where your edges diverge like they do here.

While I'm glad to see that you're using the orthographic studies in your constructions, you are unfortunately not going nearly far enough in identifying all of the major landmarks, and end up having to estimate a lot of aspects of your construction by eye. As explained in these notes and as demonstrated in the example linked from there, the purpose of the orthographic plan is to basically make all your decisions when studying your object two dimensions at a time, in a way that can be directly transferred to three dimensions. That means doing all the hard thinking when the problem is more straightforward, and then simply repeating the process in three dimensions.

In order to explain this further, I was drawing over your drill orthographic study, but I noticed another issue I quickly want to call out before I continue with the previous one. As shown here you drew the front section of the drill as though it was a 3D construction - meaning, you drew elliptical cross-sections, as though they were being viewed from an angle instead of fully from the side. As shown in my correction, those ellipses should just be straight vertical lines, as we're drawing an orthographic study. If you're unsure what that means, you may want to take a look at this section from Lesson 1 - it was updated fairly recently, and explains the differences between perspective projection and orthographic projection. The video at the top of that page also goes into it.

Getting back to the previous point, here I've gone back over your orthographic plan and marked out which of the landmarks necessary for constructing this object were defined, and which were as yet undecided and would have had to be estimated/guessed at when transferring it over into 3D. Along with most of the landmarks not being identified, you'll also note that I took a lot of the curving lines you used and broke them down into straight lines as explained here in the lesson material.

While I would have assumed that you missed this section, I did notice that your submission included this construction which is only accessible through a link in that part of the instructions. I can only assume therefore that you were aware of this, but despite that did not use the information that was provided there.

All in all, I think you may have very much rushed into this and did not give the lesson material, or your homework, nearly as much time as it really required of you. As this is something that is stressed in the requirements for official critique (which you can review in this video from Lesson 0), I am going to have to ask for a full redo of this lesson's homework.

Before doing so however, I strongly encourage you to review the concepts from the previous lessons, with some longer warmup sessions to put them into practice. Coming back after a lengthy time away and jumping straight in where you left off simply isn't feasible, and would not make it possible for you to approach this work or this lesson as you ought to.