I use an Igaging Absolute scale, that I adapted to the tailstock. It works well and is very accurate, the scales have a very slight lag time, but it is not an issue when using it for the tailstock. Batteries have been going for many months, it has an auto shutoff after a couple of minutes. You can cut the scale if needed, but need to do it with a Dremel cut off wheel or similar carbide wheel because they are hardened SS. Ideally mount the scale on the back of the tailstock if there is room. Making a bracket is fairly straight forward. Beats counting revolutions and trying to read the analog scale. I have been very impressed with the accuracy and reliability of the Igaging Absolutes, I also use their calipers.
http://www.grizzly.com/products/Absolute-Digital-Read-Out-6-/T26539
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