Beginning to burn through the pages

Here is a sample of some of the homework that I'm doing this semester. I was gone in Palm Springs last weekend and had to quickly make-up homework so I essentially had to do 40 pages plus one reworked design of a pro in 2 days! These are all free hand perspective sketches in ink of CPUs for my Industrial Design Drawing 3 class. I've been drawing so much straight lines and more that I've literally lost sensation in the tip of one of my fingers. I killed the nerve endings just from drawing too much. :/ Anyway, hopefully there will be more to come. Back to work...