I don't know jack about this book or it's author, I just found the link on woot! and thought I would share for any who might be interested in checking it out.

Free (July 16 only) Understanding 3D Printing: 3D Printing Hardware eBook: Al Williams: Kindle Store

[www.amazon.com]

Too bad it isn't available as a nook book as well.

You can read kindle in a browser at read.amazon.com or many phones, pcs, etc

I downloaded the volume and bought the set since it was a little cheaper than buying the 3 vols