Rodney V. Smith
DVXFest Promo Guru
You might consider getting a threaded DryLin. Its more expensive but would make it easier to use with servo motor and has option for hand crank. However, keep in mind the threaded rail is more expensive.
Threaded drylin seems to be an option for something like this. Might bear looking into. Seem like Igus has a built in solution for a lot of our questions already.