Starting with your form intersections, by and large your work here is coming along well, and you appear to be developing a good sense of how to tackle not only the simpler flat-on-flat intersections that students are generally comfortable with here, but also the more complex flat-on-round and round-on-round ones. That said, I did notice some cases where you were somewhat prone to overcomplicating some intersections, like those shown here. For the intersection between the sphere and the flat base of a cone, you ended up using more of an S-curve - in this case, the curve would be simpler, simply following the curvature of the sphere as it traces along the flat surface of the cone's base, right up to the edge.

Always remember that the intersections occur between surfaces, and so if we look at each individual pairing of surfaces, we can stitch together the overall intersection one segment at a time. This diagram may help as you continue working at this, although I expect your overall understanding to be fairly well developed already, with just some small areas continuing to cause you trouble.

Lastly, be sure to use the ghosting method when going back over your linework to add line weight - I noticed a fair bit of hesitation when adding those additional marks, which in turn caused wobbling and other irregularities. Mistakes happen - what matters is that we apply the steps appropriately, so that even when they do occur, we're giving our arm the opportunity to get better at applying those correct steps so that in the future, they'll be less likely to occur. Altering the approach out of fear of making mistakes will not make those mistakes less likely - it'll simply change their nature, while giving us no long term benefit either.

Continuing onto your object constructions, overall you've done quite well. I can see effective use of orthographic plans in order to analyze and lay out your plan for the 3D object, as clear signs that you're leaning into the particular focus of this lesson - precision.

Precision is often conflated with accuracy, but they're actually two different things (at least insofar as I use the terms here). Where accuracy speaks to how close you were to executing the mark you intended to, precision actually has nothing to do with putting the mark down on the page. It's about the steps you take beforehand to declare those intentions.

So for example, if we look at the ghosting method, when going through the planning phase of a straight line, we can place a start/end point down. This increases the precision of our drawing, by declaring what we intend to do. From there the mark may miss those points, or it may nail them, it may overshoot, or whatever else - but prior to any of that, we have declared our intent, explaining our thought process, and in so doing, ensuring that we ourselves are acting on that clearly defined intent, rather than just putting marks down and then figuring things out as we go.

In our constructions here, we build up precision primarily through the use of the subdivisions. These allow us to meaningfully study the proportions of our intended object in two dimensions with an orthographic plan, then apply those same proportions to the object in three dimensions, and you've leveraged that to great effect.

I have just a couple things to call to your attention, or for you to keep in mind. The first of these is fairly superficial - I noticed that in your drawings you tend to leverage form shading. While this isn't inherently a mistake (due to the age of some of these demonstrations, you'll see me using them there too - that's something that'll be fixed when I'm able to create new demonstrations as part of the course overhaul I'm slowly picking my way through), it does go against the recommendation in Lesson 2 of leaving shading for shading's own sake out.

There is however a situation where the kind of hatching I employed on the rounded corner of the bluetooth speaker demo would be appropriate - mainly where we're dealing with a form that does not necessarily already imply that its surface is curved, and we want to more strongly reinforce the idea that it is. So with the bluetooth speaker, we've taken a box and rounded off that corner. With all of the other constructional marks we have present, it may not on its own be clear enough that the corner is rounded, so adding a few bars of hatching does help. This is not however necessary on a standard cylinder, as that is already fairly clearly rounded, and that is part of what students expect when they see the basic linework of a cylinder.

Another point I wanted to make is of the importance of using the tools we have at our disposal - even when they seem really minor or unimportant. For example, we know that in order to construct a cylinder we can employ the minor axis line to ensure that the ellipses are aligned correctly, and that we can even build them up within a box in order to help us orient that minor axis line more effectively. That is something I think would have definitely helped with the buttons on this gamepad here - the cylinders appear to be a little skewed to the side, rather than being entirely upright. To that point, it also would have helped to have plotted out each button's specific footprint on the controller's surface - that could have been done in the top-down orthographic plan, which appeared to mainly focus only on laying out the overall body, rather than the layout of the buttons which were left to be estimated instead.

It can certainly be tempting to skip steps, but what we're doing in this course really benefits from being as complete (to the point of tedium) as you can, even if it doubles the amount of time required of you. Ultimately everything we do in this course is to train your instincts, and we can only do that by being as purposeful and intentional with every decision as we can.

Anyway! All in all, you're progressing well. I'll go ahead and mark this lesson as complete.