Potentiometer Suggestions

[GeeTwo]

Potentiometers with much more than 1/2 turn are unusual, though there are a few, such as this 10-turn pot from Jameco. Less expensive than an absolute encoder, but you'll lose most of the dynamic range as you're only using one revolution, and it's easier to break. OBTW the sweep is the contact farthest from the shaft, not the one in the middle like most pots.