If anyone's interested in creating a rotating control like the blade in this little app (attached project file "rotatingControl.zip"), feel free to see how I did it here. It's not perfect (I'd have really liked it to spin freely for a time after the touch end depending on velocity of the touch move, but I ain't smart enough to have figured out how to achieve that.
This is just a little app I made for my work. It simply tells me the angles to tilt and rotate my crosscut saw for compound miter cuts in crown mouldings, depending on the angle of the corner to be mitred.
Most of the code is inside the PanGesture1 action event.