Over the last 3 moths I have been using the Kessler Crane shuttle pod as my primary motion control system. Its ability to tear down into 4-foot sections, and its fast onsite setup has made it my default motion system. I have come to the conclusion that size does matter. The ability to shoot a 20 foot motion rail shot vs a 4 foot motion shot makes all the difference in the dramatic depth of field shifts that I want for the effort to setup rails for a shot.
The shuttle pod is a simple but stable design-using squire tubing connected with aluminum stays. A sled aka Shuttle Pod is attached to the top and uses an omega drive belt system to pull the sled across the track.
To setup of the shuttle fist pull out and attach the rails
Then attach the rails with the center braces.
Use the 1/4 20 bolts to build the rails
The rails are then attached to the end braces
Then the shuttle pod is build
Run the belt down the length of the track and use the end belt connectors to fastend them tight
Thread the belt though the drive using the powerd on basic controller.
Now set up the shuttle pod movement and program your timelapse.