My BIY Band Sawmill Railbed : 19 Steps (with Pictures) Instructables
This gave me the needed amount of round tubing for both sides of the railbed. Cut the rectangular tubing to length and the round, both ends on a 45 degree angle. Lifted the top rail bed off the bottom rail, installed/welded all the 2" x 4" rectangular tubing spaced equally, then all the round tubing, making sure everything stayed in level.