Edit: Since this video was uploaded the "Construction" article mentioned here was removed and integrated into the 3rd part of Lesson 2, so at this point you should already be familiar with it.
You can find the full lesson here: http://drawabox.com/lesson/3, but don't forget to complete lessons 1 and 2 before starting this one.
Drawabox is a series of free structured drawing lessons that explore the basic mechanics of drawing, along with the fundamental skills of capturing the illusion of solid form and constructing complex objects from their simplest components.
You can find more free lessons at https://drawabox.com
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