Mechanism

I am working on a design that uses Family Tables to create several
variations of the model. Each model uses a hydraulic cylinder. The
hydraulic cylinders have a different stroke for each model and these
are also created with Family Tables.
I need to have each model work as a mechanism but I am having a
problem with the stroke distance. I create a servo motor for say a 6"
stroke, which works great. Then I open a different stroke cylinder,
say 8", and create a servo for that one, which also works great. But
when I return to the 6" stroke, it now moves 8" (or what was set
last). I have to change the value in the current servo motor back to
6". Now, of course, the 8" won't work right when I go to that one.
I have tried creating the servos from each Family Table version by
creating separate servos for each but it doesn't work. Does anyone
know how to solve this? Is it possible to do this in WF2?

Thanks Peter