how about you go to your local steel supplier and buy a serious piece of channel 20 feet long and have it cut in half, it comes 20 feet long and ask about the strength of the steel and get it a little wider than your tracks
just another idea and tell the guy what your machine weighs with your attachment and he can let you know what size will work, I am expecting a huge piece
In my garage for the second floor, I bought a 16 inch H beam, it weighs 31 pounds per foot and it real strong, here is picture of it
Jim
