On the t track and t bolts from Rutlands, how much play is there between the two? If running a fence between 2 of the bolts at either side of a table saw table (T tracks running parallel say 18" apart), would it be possible to move the fence out of square simply by moving it forwards and back? Is there any way of avoiding this, by say machining a profile from acetal that is a couple of inches long and a tight fit?