So you've done an excellent job throughout this lesson, but before I get into the actual critique, I do want to touch upon what you mentioned in your comment. It's completely normal to feel overwhelmed by the density of construction lines, but as with basically everything throughout this course - like drawing from the shoulder, for example - just because something is hard doesn't mean we are better off avoiding it. There will likely be situations (specifically in Lesson 7) where shying away from the use of additional contour lines will leave you without enough concrete structure upon which to build things with the kind of specificity and clearly defined spatial relationships that will be needed in order to make the construction feel believable and solid. This lesson is intended to be a first introduction to working with a fair bit of construction lines, and to get used to sorting through the mall.

Honestly, I actually don't see any real issue with the amount of construction you employed here - it doesn't really feel like you minimized much (except some of the lines that seem to have come out a little more broken as if the pen itself was malfunctioning), it seems to me like everywhere you needed additional construction to help position elements with more specificity, you did so. But still, I wanted to be clear on this point - dealing with a lot of construction lines and sorting through it all does get easier with experience, so make sure you don't avoid it.

So, moving onto your work, your form intersections to start are demonstrating an exceptionally strong understanding of how these forms all relate to one another in 3D space. Your intersections are spot on - usually at this point I'll still catch the odd mistake or two, but I'm not seeing anything that stands out.

Moving onto your object consturctions, despite your misgivings regarding construction lines, you seem to have blocked everything in where necessary. Even the additional lines used to define rounded corners and bevels were blocked in with exceptional specificity - you really didn't skip any steps here.

The last drawing - what I assume to be either a staple gun or a hole punch - was phenomenally well done. The solidity of the structure, and the specificity of how you handled the curves - first blocking them in with straight edges, and only rounding them out towards the end - really came out well.

Aside from the smallest of nitpickings - like the alignment of the ellipses on the cylindrical form at the top of this machine, and the hatching that kind of served to make an otherwise precise and cleanly defined drawing a bit sloppy - your work is spot on.

I do have one recommendation for the construction issues - when you get to the last lesson, draw your vehicles with a ballpoint pen. You've done some excellent stuff here with the fineliners, but ballpoint makes it a lot easier to deal with a lot of construction lines all flying around, for precisely the reason we haven't been using them til now - we can draw more faintly with them with relative ease. You've obviously made excellent use of your fineliners and have shown your capacity for confident linework - so there's no harm in taking the permission these last couple of lessons give you to work with a slightly more forgiving tool.

Anyway, I'll go ahead and mark this lesson as complete. Keep up the fantastic work.