It depends on what you need the
track to do. Are you looking for a guide
track that just keeps the
wagon moving along the right path? This can be as simple as a slot routed or circ' sawed into the
deck with a corresponding pair of knives on the
wagon. Are you looking to automate the move as well? Even this can be done with the above method in some cases if you run a cable through the
groove and onto the knives. For heavier or more complex automated motion you'll want to go to a
mouse track system like what Footer linked. This requires a
deck that is built up several inches with built-in slots for driving "dogs" or "mice", drive cables or chain as well as diverting &
turnaround sheaves or sprockets. If you're looking for a
rail system that actually supports the
wagon with metal wheels on metal rails (ie-to reduce rolling friction on large units and save the floor from the wear and tear of wheels over a long run), then that's something else entirely.
And then you have to consider the impact of various solutions on the show. In particular, how tolerant is the show going to be of slots cut into the
stage? Can your dancers tolerate a 1/4" slot? a 1/2" slot? Will your director/
scenic designer tolerate a set of lines in the
deck cutting
clear across the entire
stage?