Really great work! You started off pretty strong, but with definite inconsistencies in the convergences of your lines (though within a pretty small range, they didn't immediately stand out as all that bad), and steadily improved throughout the entire set. On top of that, your linework is confident and the resulting forms feel solid and believably three dimensional. All in all, I think you're doing a good job of focusing on the core aspects of this challenge, and have put it to great use.