Ultimaker 3 positions belt tensioner

Simple but effective multiposition belts tensioner for Ultimaker. You can use from 1 up to 3 bolts to make tensioning you need (from small to very high). It is possible at least 5 different tensioning levels with this thing (you can easy understand how once you'll drive in one or several bolts).

PS: Source in SolidWorks 2012 format also included.