For those wondering just what's inside, Mike (of Mike's Electric Stuff[0]) has some excellent teardowns with commentary on a few[1][2]. The engineering constraints (high reliability with low maintenance, instructing the user how to operate it, etc) make them very interesting machines.<p>[0] <a href="http://electricstuff.co.uk/" rel="nofollow">http://electricstuff.co.uk/</a><p>[1] <a href="https://www.youtube.com/watch?v=pn-Wv9YAfv0" rel="nofollow">https://www.youtube.com/watch?v=pn-Wv9YAfv0</a><p>[2] <a href="https://www.youtube.com/watch?v=eWC22NufDUo" rel="nofollow">https://www.youtube.com/watch?v=eWC22NufDUo</a>