This is a new centrifugal water pump for my MakeItFloat challenge submission: The Catfish - A fully working submarine http://www.thingiverse.com/thing:920376 This pump has been rebuilt to fit a 550 motor with a water cooling jacket: http://www.hobbyking.com/hobbyking/store/__19444__Water_Cooling_Jacket_for_36_Size_Motor.html The small hole on the side is for priming the pump and water cooling the motor. All new files - entire_thing.stl is now for reference onlyPrint completely solid. Put the motor in the housing and attach the impeller. Glue together with acetone making sure the motor and impeller can move freely.