The process begun to get the rails square and parallel to one another.

It started by getting one rail secured to the 5x5 tube in a straight line using a long straight edge to make sure there was no gaps. Once it was secured down, the second rail was secured down using cap screws and a hydraulic jack and long wood clam were used to push or pull the rails closer or farther apart to get them perfectly parallel. The final test for parallel involved installing on of the bearings on the rails and rigging up a dial indicator to run along the opposite rails edge and watch the indicator change as the bearing and indicator tweak the rail until the dial indicator didn’t move at all over the entire length of the rail.

Now that the parallel was done, it was time to check for dips and humps along the length of the rail. We used a vision system (transit) to see the highest point on a rail and then shim under all of the other bolts to get them all perfectly level. Once the first rail was perfectly level, we used the dial indicator again, this time on the top surface of the rail to run it along and determine how much needed to be shimmed on the other rail. Once the amounts were know, corresponding shims were made up and the re alignment process was done with shims underneath. The end result was 2 rails, perfectly parallel and flat with in 5 thou over the entire span.