this work contains material previously published as : do-it-yourself gravity , the hoverboard series isbn-10 : 0692237097 isbn-13 : 978-0-692-23709-0 v1.3 moved soundtrack www.mitty-walters.com give feedback on the book at : www.facebook.com/mittywalters mittywalters1 @ gmail.com acknowledgments dedication for my beautiful , sweet , long-suffering wife and for the three coolest little dudes on the planet .