[billbo911]

Originally Posted by Mark McLeod

After you find and fix your wiring problem, it also sounds like you should be using a 3-turn pot to get better resolution.

Better resolution means more accurate positioning of your arm.

The first thing to do is get a 5k to 10k 3 turn pot. 100ohms will likely load the analog board too much and yield poor results.

Then, for absolute best resolution of position, try to match the number of turns as closely as possible. Always make sure the pot can travel a bit more than the actual turns needed, but not by too much. Most pots don't handle being turned past their end point. Although, continuous pots don't care, but they seem to come in single turn only.