Full size replica of the worlds first "successfully produced" engine. 1/2 HP 1867 Otto Langen engine made by Grenning Models. 10 feet tall, 2500 lbs & 50" flywheel. The physical project started June of 2015, completed Spring 2017. Research for it spanned a couple decades, Measurements taken were taken on several existing engines including the original engine Serial Number 1, (still exists today) in a private museum (Deutz Technikum) just outside of Cologne Germany. What a fantastic project this has been.